I've been playing co-op campaign with a friend and we've encountered a glitch in the Chapter 2 Vikings mission with the Valk in the myre.
After going through the first objective, a cut scene takes place and then a new objective is set.
We progress forwards and then we get an error connection.
We had this occur to us 3 times in a row.
We've never had network issues during co-op before those moments.
Please see video from 36:00 on wards.
https://youtu.be/CyYtL1itRmg
(I uploaded it from playstation 4 onto youtube.)
p.s. I could not find a place to report bugs on the forum. So I have had to upload it here.