Confirmed. We're facing this same issue with multiple web apps.

Webgl canvas is causing massive memory leaks on iOS 14 which may be the reason for the silent crashes and reloads. Learn more: https://developer.apple.com/forums/thread/668999

This memory leak might very well be the reason for thousands of sites crashing and randomly reloading as reported here: https://developer.apple.com/forums/thread/662251

Still no word from Apple after three month. This bug is impacting thousands of our platforms iOS users alone. Is it a webkit issue? Is there a better place to report this?