missing co-pilot conversation history after update:

I have updated Co-pilot this morning.  when co-pilot restarted my chat history/ conversations were uploaded... except for one. the affected conversation started in January 2026 and is significantly larger than your other chats (a project based sparring exchange).  I refreshed, but that did not work out: error message ("Unable to load"/white screen. other smaller conversation did up-load correct. I use Copilot app version macOS Tahoe 26.6.2 version. support could not help me and send me to this platform....