We do need a test file and there would be no ambiguity about the test case if we can use yours. You can put it in drive if you like, and share with my google account if it contains corporate sensitive information.

I don't know how monorail does with very large attachments, but you could also try that.

I opened the file locally and indeed it displays tiles that are entirely solid color, mostly black but sometimes some other color).

I think this is basically GPU out of memory errors. The big black blocks align with tile boundaries, indicating a failure to allocate ( I think) the tiles for painting.

Over to CC team to confirm: Do big black, or sometimes greenish colored, solid tiles on a big document mean some kind of memory exhaustion?

This is another case of an enormous page right?