I've had the same issues in the past, and was stable for several months (with very rare DX11 crashes) and the game has just become unstable and unplayable for this problem again.

Things I've tried in the past, in addition to the Dev recommended issues:
-Ensure overclocking is disabled (laptop came with it at factory, I don't use it)
-Clothes any other RAM hogging programs like Chrome
-Ensure G-Sync is disabled
-Basically close any other applications
-Update GPU drivers
-Clear user files
-Restore game from launcher
-Reinstall game
-Reinstall Windows

This problem is not new and has not been fixed for 10 years.

In around 2012 I started having this on my previous computer and my subscription was about to expire so I left the game then. I came back in Jan 2022 and I just started getting caught up on endgame content this week; I'm probably not going to get my goals for this week before going back to work met due to this bug. If my subscription had not renewed last week, I might have left the game over it again.

DXDiag shows no issues and I do not have crashes in any other DX applications.

I'm following this post as I would also appreciate seeing it resolved ASAP.