I'm having an issue where the scale visiblity settings on layers within a basemap are being ignored after the basemap has been switched in the web app builder.
I have a custom basemap which contains three tile caches. One is set to view when zoomed out and it then switches to the other two when zoomed in.
e.g. when zoomed out
and when zoomed in
This is how it is saved in the webmap (which is shared with the basemap group)
There are some other basemaps as well which contain either one or two tile caches.
This is the webmap used in the web app builder https://marlborough.maps.arcgis.com/home/webmap/viewer.html?webmap=3c12c954d2394241971edbbb097d6822. If you change basemap from the default 'MDC Basemap/Aerials' to something else e.g. 'MDC Topographic'. Then change back to 'MDC Basemap/Aerials' this all seems to work ok.
However. In a web app builder pointing to the same map https://marlborough.maps.arcgis.com/apps/webappviewer/index.html?id=09b642b595d24ab8afed5b476b8e55e1, if you change basemap tool and do the same thing as above, the scale settings are ignored and the three tile caches display at all levels when you switch back to MDC Basemap/Aerials.
Help..... is this a bug?
It looks like exactly the same thing happens when using the Web App Builder in Portal (10.7)
For anyone else who looks at this, it is apparently already a known bug
When a custom basemap is created with a visibility scale set from a webmap, upon switching basemaps in Web AppBuilder for ArcGIS and switching back to the custom basemap, the visibility scale is not honored.
Still a bug in 10.8.1 and AGOL as of Sep 2020.