So when trying to play with my friend in Far Cry 6 co-op, he gets disconnected after ~about a minute with the error bookworm-2cea2bdc.
We had this issue with New Dawn, in which this particular error code seems to be a ping related problem. He is in Denmark, I am in New Zealand. We played Far Cry 5 together, start to finish, zero issues. I spent a lot of time in the New Dawn forums to finally be told "Oh it's a ping limiter, if the ping is too high it disconnects you." Hoped Far Cry 6, being a full sequel rather than a mini game wouldn't have this issue.
It should be up to us whether the ping is too high to play, not up to an arbitrary system programmed in to the game.
My NAT is open, we can play together with zero issues for that minute, so it's definitely playable.
An answer from Ubisoft on whether this is intended and whether they would consider removing this crap would be really grand. We waited a long time to play Far Cry 6 together and it's really disheartening to run in to this issue again.