Tell me about it. The 787 was my goto long haul. I have wasted 3-5h trying to get the autopilot to work. My 2020 SimBrief Flight plans that were just fine have been knee-capped. BTW, flies like a ton of bricks.
I resolved this afternoon to just leave it alone hoping they will fix it, but it is the same story on many other aircraft including the C-172… I tried the autopilot on that too and 