This was updated back in March, but just wanted to close the loop on the issue here in the community too and gather all the posts about this together in the one place for posterity.
We released the update on March 26, which was just before Apple’s April deadline:
https://docs.thunkable.com/release-notes#mar-26-2020
cc: @sam_mo @Chris @L3on @steveh @Carlos_Bieberach @IWS
Hope that you iOS apps are working well with the new and improved web viewer!