which character talked to the slave traider the first time?
the 2nd time it will auto select the main character unless that person is too far away to join the talk... i know you have now moved on but that is how you can work around this
and yes The_Red_Queen is correct that this new patch 9 change causes more bugs than it fixes
as a side issue, running the game from BG3.exe instead of letting Galaxy fire up the Larian launcher makes the game more unstable... at the very least you should set the exe to run as admin by default when it fires [that will help]
