After her initial camp talk and recruitment, i can't talk with her anymore.
Only way to get her out of the party is travelling back to act 1, but i can't add her back after that.
I have the same bug. Got it with patch #4. It continues with patch #5, meaning: #5 does not have a fix.
Karlach successfully recruits Minthara, whose joining is unanimously approved by all 3 party members. However, after Karlach sends her to the camp and she accepts Karlach's invitation to become a permanent companion, nobody can talk to her any more.
I reported it to Larian as a bug. The bug report confirmation email says that Larian developers will read every bug report in the order they are submitted.
