Noted thanks @sebavan we will stop all dynamic canvas resizing on iOS till safari fix this. We noticed that in 17.1 it was partially fixed in that when we switch from one size to another it’s now ok but with page scroll and bottom bar causing the canvas to change size it’s crashing. Seems like each iOS version they do something fun for us to implement short term fixes for. 
Thanks for the guidance we will check back and update this post when we know it’s fixed so others can benefit from this information.