Yeah I’m no expert, but ths looks like extrution issue to me too.

My H2S looked similar in one corner, as the bowden tube from the factory is a tad bit to short, so the feed was uneven when it was curved/stretched to the max.
Replaced it with a 3 cm longer one, and it worked fine again.

I’d try a cold pull, then smaller test pieces. No point printing the whole bed when the issues are everywhere. When it’s nice, test the whole plate.

Good luck!