Vector tile layers not displaying in ArcGIS JS 4.9 on Google Chrome in iOS 11.4.1

[AdhikariBishrant]

Vector tiles are not displayed in Chrome (v 69.0.3, latest one) running on iOS(11.4.1). The same application works on safari in iOS 11.4.1 and on iOS 12 (all browsers). Also when the JS API version is changed to 4.8, everything runs smoothly. There are no basemap load error or any exceptions in loading a view. Are you guys having similar problems ?

P.S see attached images of same application with 4.8 and 4.9 api on iOS 11.4.1 chrome 69.0.3.

[DavidColey]

I can tell you that my collaborated version of the human geography basemap does not load into 2 of my large web maps with 20+ hosted feature layers.  It just started flaking out yesterday and won't load as one of my basemaps from my custom basemap gallery.  It's strange because I have 12 other webmaps where this is not an issue.

In my WAB Dev 2.8 version, the basemap gallery won't load the basemap either, but again just in the apps with large layer counts. Kelly Gerrow maybe you've got an idea?

agol content

[DavidColey]

In WAB Dev 28 I can also report that my console log shows a:

Warning: Too many active WebGL contexts. Oldest context will be lost. VectorTileLayerImpl.js:630

My guess is we're suddenly having trouble accessing the pdf files, e.g.:

https://basemaps.arcgis.com/arcgis/rest/services/World_Basemap_v2/VectorTileServer/tile/10/431/276.p... 

maybe from a security update?

I don't know

[DavidColey]

On the other hand, none of my other apps with less than 21 hosted feature layers is having an issue so I'm stumped.