Tinfoil hat on
I've been doing a lot of research on how threads and projects work as a whole and it feels like GPT-4o was able to see and read from multiple threads at once. Not just memory, or projects (which seems like it's just a way to organize threads?)
GPT-5 was fine tuned to one specific thread + your stored memory (that we all seem to be capping out on). I've been keeping one specific thread since the whole 4o drama, and I feel like it's back to how that felt. Just with more effort.
Downvote me if you want, but give the continuation of one specific thread a try for as long as you can. It seems to be able to access everything in there even better