Can confirm, Karlach especially has a lot of banter with Shadowheart and I wasn't having any, maybe max 1-2 dialogues and that was all in act 1 alone. Rest is muted to a deafening margin from act 2 onwards. To be honest, banter should not have limits, at least not before middle of act 2 to act 3.. It'd feel a bit weird if you exhaust all banter in act 1, and the rest of acts not have any.
Lots of stuff happening in the city of Baldur's Gate and my companions don't even talk? Not even talking about stuff that happened before entering the city or random interesting stuff you get to know about your companions? Datamines have showed that Minthara has a lot of banter for each companion and she's been so far mute with the ladies. Even with the dudes.
And weirdly, when I add Gale to the party or Wyll or Astarion, banter immediately starts and its all directed at Shadowheart most of times.
Banter should still be happening in act 3, even if scripted.
