Network Game Slow/Unresponsive

I sometimes had this problem in the old fm, but not very often. I join my mates network game now and when clicking through messages, looking at the tactics screen etc it takes like 5 seconds to load, instead of instant, then when you try and continue it takes much longer than normal, just very slow and not playable.

Does anyone have anything we could try? It's just the same when he tries to join mine, any help would be much appreciated, thanks