Im playing a Warlock and these are two System breaking bugs i encounter on only one character.
Hellish Rebuke stops working past level 7. It still shows up in your spells but not in your Reactions. This bugs seems to be on every Warlock (other poeple seem to have the same issue:
https://www.reddit.com/r/BaldursGate3/comments/15hs15a/hellish_rebuke_does_not_trigger/) Seems like they forgot to make a 4th and 5th Spellslot level version.
Spell sniper only gives you cantrips and deosnt affect your Critical hit Chance (Spells and Cantrips still dont crit when rolling 19). Wich makes this feat pretty useless.