topic Re: Basemap Map tool shows double custom basemaps in ArcGIS Experience Builder Questions

Basemap Map tool shows double custom basemaps

DavidColey — Mon, 27 Oct 2025 14:25:33 GMT

Hello - The basemap tool in the Experience Builder map tools now shows custom basemaps in the basemap gallery twice when a custom basemap is used as the webmaps basemap.

When a custom basemap is not used as the webmap basemap, for example the Streets or Topo, this is not an issue.

To see what I mean you will see the "Sarasota County Local (Vector)" basemap twice:

https://experience.arcgis.com/experience/36f63bf761e4483b9e89120efe8ed860

The webmaps in this app use a custom localize basemap with some vector tile layers. When the user opens the basemap tool, this custom local basemap appears twice.

I am not seeing my custom local basemaps twice in my AGOL custom basemap group, the webmap count making up the basemaps show as expected, i.e there are no duplicate webmaps. The AGOL custom basemap group does however participate in a distributed collaboration, where I send the custom vector tile layers to the group by reference from our guest Enterprise Portal.

Thanks-

@Jianxia

Re: Basemap Map tool shows double custom basemaps

Ke_Xu — Tue, 28 Oct 2025 03:21:23 GMT

Hi @DavidColey,

Does it mean that these two basemaps are duplicated?

Thanks,

Re: Basemap Map tool shows double custom basemaps

TonghuiMing — Tue, 28 Oct 2025 03:38:49 GMT

Weird...this is what I see, and I do not find the duplicate ones

Re: Basemap Map tool shows double custom basemaps

DavidColey — Tue, 28 Oct 2025 13:40:59 GMT

That is strange @TonghuiMing - your screen shot does not show the custom vector tile layers making up the basemap - it is only showing the light gray base. The screenshot from @Ke_Xu is showing what I have been seeing - and am seeing this morning - 2 basemaps that are only being duplicated in the basemap selector tool.

This local basemap at:

https://sarco.maps.arcgis.com/home/item.html?id=32f5e05a349d4dc98bc2ce90b34e4f04

consists of the following:

Light Gray Reference - US - Copy

https://basemaps.arcgis.com/arcgis/rest/services/World_Basemap_v2/VectorTileServer

Local Detail labeling vector tile layer:

https://ags3.scgov.net/server/rest/services/Hosted/CountyBaseDetail/VectorTileServer

Local Base vector tile layer:

https://ags3.scgov.net/server/rest/services/Hosted/SarasotaCountyBase/VectorTileServer

Light Gray Canvas Base:

https://basemaps.arcgis.com/arcgis/rest/services/World_Basemap_v2/VectorTileServer

Both of the basemaps.arcgis.com layers will not update their sharing, so this is probably all related to the Online update.

Re: Basemap Map tool shows double custom basemaps

DavidColey — Tue, 28 Oct 2025 13:46:56 GMT

Also @Ke_Xu and @TonghuiMing - If you go to my experience here:

https://experience.arcgis.com/experience/48741ab2a7b24c0fb5f360d0f40824d5/page/Home

All 3 of these maps use the Living Atlas world topo as the webmaps' default publication basemap, and you can see that there is no issue of the 'Local' maps being 'duplicated' in the experience basemap map tool.

Thanks

Re: Basemap Map tool shows double custom basemaps

MattiasEkström — Wed, 29 Oct 2025 09:59:39 GMT

If I go to https://experience.arcgis.com/experience/36f63bf761e4483b9e89120efe8ed860 I get this

That's my custom basemaps in my ArcGIS Online organisation. They are completly irrelevant in that experince, I suppose that's not by design? I should add that I was signed in to my AGOL account in that browser.

If I use the same link in another browser where I'm not signed in I get this:

Without the duplicate. However, if I change the basemap, close and open the basemap gallery then the duplicate shows up.

Re: Basemap Map tool shows double custom basemaps

DavidColey — Wed, 29 Oct 2025 13:48:33 GMT

Thanks for the feedback here @MattiasEkström - No, you seeing your custom basemap gallery is not by design as far as I know, I've never seen that before..... your second screen shot is what everyone should see.

I now see this in a Chrome browser if I open - close - open the basemap tool:

That is to say, no basemap tiles pull in from the top 'duplicate' local custom basemap (or any network traffic at all). when using Chrome or Edge.

The console shows the reason why:

The basemap has already been destroyed.

Interesting. Again, thanks for looking at this.

Re: Basemap Map tool shows double custom basemaps

DavidColey — Fri, 31 Oct 2025 13:32:14 GMT

@Ke_Xu , @TonghuiMing - Good morning. After much examination and troubleshooting, this issue appears related to the Living Atlas content update and the ArcGIS Online update. That is, I examined one of my Enterprise 11.5 portal hosted experiences and they too show this same basemap issue.

I upgraded the Living Atlas content to 2025.2 for our Enterprise on 10/21 and it now appears that any basemap where I am mashing custom vector tiles with Living Atlas reference layers, and that custom basemap is used as the webmaps' default basemap, will create the 'duplicate' map in the basemap tool.

@MattiasEkström

Re: Basemap Map tool shows double custom basemaps

TonghuiMing — Mon, 03 Nov 2025 06:53:14 GMT

Emm, that is interesting news. I wonder what they've done to cause this.

Based on our developers' investigation, these two have the same URL, but one has maxScale & minScale, the other's values are 0 & 0:

They have different scales, thus they are listed separately, as different basemaps. Not sure why though...

Re: Basemap Map tool shows double custom basemaps

DavidColey — Mon, 03 Nov 2025 14:03:06 GMT

Hi @TonghuiMing - would it be possible for you to share more of what you are seeing in the console log, for which app or service, and where you are locating it this descrpancy in the console?

The only vector-tile service I have listed from my host site that could possibly match the url stub I see in your screen shot is this:

https://ags3.scgov.net/server/rest/services/Hosted/SarasotaCountyBase/VectorTileServer

And this service does not show 0,0 for a minScale, maxScale

Thanks

Re: Basemap Map tool shows double custom basemaps

SubodhDhakal_NZTA — Thu, 04 Dec 2025 02:27:08 GMT

We have come across this exact issue and wanting some clarification from Esri dev team. Any updates here how we can mitigate this ?

Re: Basemap Map tool shows double custom basemaps

DavidColey — Thu, 04 Dec 2025 14:01:28 GMT

not from me, the last feedback I received was from @TonghuiMing last month. It's not something that is fixing itself on its own, apparently.

Re: Basemap Map tool shows double custom basemaps

DanielWebb — Wed, 21 Jan 2026 15:24:01 GMT

I don’t know if this will help, but we also kept getting a duplicate basemap in the gallery. We have some custom imagery that is layered on top of the Esri World imagery, so in the web map we added a visibility range to our imagery so as not to show until zoomed in. This created a duplicate basemap in the basemap gallery. When we removed that visibility range, the duplicate also disappeared in the gallery. So ExB must create a weird duplicate simply by customizing the properties by web map? I don't know. It's definitely an Esri thing on the backend or something.

I don’t know if this helps your situation. Figured I’d just let you know what worked for us.

Re: Basemap Map tool shows double custom basemaps

DavidColey — Wed, 21 Jan 2026 20:44:37 GMT

Yeah that did work, thanks for this @DanielWebb Yes it has to do with the visibility scales. Although I am using the standard web mercator visibility scales for the vector tile layers that I include as part of my custom webmap basemaps, I am not using all levels that are present in the default world topo or world imagery. i.e levels 0 - 21, I'm like at 15-20 or 13-21 depending.

But regardless, re-setting the visibility scales to all be World - Room in my webmap-basemaps, that seems to have done it.

Re: Basemap Map tool shows double custom basemaps

SarahNoakes1 — Thu, 19 Feb 2026 09:43:53 GMT

By default, some of the Living Atlas basemaps have a threshold:

Dragging the slider to "Room" (or 1:0) has fixed the duplicate basemap issue for me 🙂