I didn't play Patch 5, so some of these could be older bugs, but as of Patch 6 I've noticed a few cinematics that are now broken that were fine in Patch 4 and prior patches.
These include so far:
1) When Astarion
tries to bite you at night
the game doesn't switch to the cinematic camera, but remains in the standard top-down viewing angle.
2) When Nettie leads you into the clinic's inner room and confronts you about the tadpole, the game once again does not switch to cinematic camera.
3) When in conversation with the tiefling child merchant Mattis, if you pass the Perception checks to
catch Silfy picking your pocket
the second scene doesn't trigger, and the involved parties just stand around.
4) When first meeting Astarion, when he rolls away and gets to his feet, his legs are bent at unnatural angles, and sometimes during this scene the cinematic camera angle is wrong and he is entirely out of frame.
5) When arriving at Waukeen's Rest, if you speak to Gauntlet Yeva at the main doors, the game once again fails to transition to the cinematic camera.
6) In some cutscenes where NPCs are wielding crossbows, such as when you first meet Karlach or witness Arka
attempting to kill the goblin prisoner
the crossbows are held at an odd angle where the handle of the crossbow, where the trigger would be is sticking out to the right, meaning the bolt is pointing left of the target, and the NPC's trigger hand is empty.
7) In conversation Zevlor has a black line that frequently appears in between strands of hair, that seems to be flickering and travelling toward the back of his head. I suspect it may be caused by the flickering flame in his eyes, as that is the only moving visual effect on him and he is the only character I have encountered who has this problem.
8) When first encountering Auntie Ethel at her shop in the Druids' Grove, at the point in the conversation where she turns to her table to find a potion for you she suddenly turns invisible. She becomes visible again when she turns back to you.
These are just the cinematic bugs I've encountered so far, but I've yet to encounter the githyanki patrol or go anywhere in the Goblin Camp or the Underdark. I will update this post with any new cinematic bugs I find after doing so.