I have also been experiencing the same issue. I can understand since my chat is probably about a year old know, but that’s besides the point.
So when I talk with ChatGPT I did make it update it’s memory in the most key and essential parts of the conversation.
I figured out that if you ask ChatGPT about their memory from the previous chat (or ask in some similar wording) it’ll remember all the information stored in its memory.
I hope this helps!