Insane lag in maps with friend

Played the whole campaign with a buddy absolutely fine but if we try to map together the latency graphs go insane and it becomes unplayable. Sometimes it sorts itself out a few mins in or it just stays like that. As soon as we attack in maps everything desyncs and we are just stutter stepping about.

Back in hideout we both have under 40ms and no problems. In single player no latency issues whatsoever.

also having this issue for australian servers, pls fix