Chat Memory function seems to be random

I am building a custom gpt (Pro member here) one was a test build in which the memory function seems to be working fine - in fact if I ask if the gpt can remember across seperate sessions it gives an affirmative answer and acknowledges the memory feature is enabled.

I’ve then subsequently tried creating another build and the memory function is not acknowledged and there is no persisting memory I found this out the hard way after building a data framework that took about 6 hours to analyze, i accidentally refreshed and the framework was gone and no history of it can be recalled even after prompting it to remember.

I’ve then tried creating 3 other gpt’s thinking maybe it was a glitch and now no custom gpt is acknowledging the memory function being enabled (even though it is checked off in my settings) nor does it say it is capable of persistent memory only per session context. What gives?