Something about this 3D transform causes a rendering issue in Safari: https://enshrined-awake-grip.glitch.me See video here: https://twitter.com/_developit/status/1618475503395938304
This got fixed in WebKit trunk by bug 248282. *** This bug has been marked as a duplicate of bug 248282 ***
While it is technically fixed, it also relies on a macOS/iOS software update that hasn't been released yet. Sorry. A fix is coming though!