Campaign broken?

I’m stuck on Act 3. Tried several different routes through the level but keep getting stuck at save points that just keep grinding or npc characters getting stuck preventing further progress. When I load my save, all level progress is lost.
After four attempts I’ve hit my limit of making no progress & having to replay the same section over and over.
I was really enjoying the campaign up to this point. Please fix and get this game running like it should be.