Oh, now I wonder what kind of bugs would produce such a straange result…
Guys, this thing isn’t a bug and never was. All this time, the broken pagination was caused by feature flags enabled on your accounts. You were deliberately included in an experiment, even though you’re paying users. Some accounts still have the old experiments enabled. But over the last few days, there’s been a much broader rollout. This is no longer an experiment.
The messages endpoint has now been changed
from
/backend-api/conversation/<conversation_id>
to
/backend-api/conversations/<conversation_id>?include_has_versions=true&num_turns=10.
My guess is that this is part of the promised conversation optimization: reducing browser load in long threads and making them load faster.
Because of the new endpoint, the full conversation tree is no longer being loaded. It’s still stored on the server, though, so it can still be accessed. For now, my patch makes ChatGPT use the old endpoint instead. If they leave the old endpoint in place, we’re good. If they remove it, there probably won’t be much we can do about it.
Thank you for the patch it worked for me 
I’ve reached out to staff, they actually forwarded me to a real person who asked for a screen recording of it happening.
I sent that off along with all the information I know, just waiting to hear back from them.
Hey, is there any chance I could get an explanation or walk-through on how to download your patch and use it properly? This is my first time trying to do any of it. I downloaded what I believe to be the correct file, but when I go to open it, it keeps saying it can’t because of a syntax error, so I can’t get it to show up in my downloads in order to put into my chrome extensions.