Lag in coop / strange behavior?

Noticed some strange behavior since yesterday.
When reaching the loading screen for coop, i see the other player has already fully loaded. But then it switch back to zero and he/she and i begin from 0.
Most times im faster and already switch to the map, while the other player is still on the loading screen. In the map im able to set move-commands and to watch the ai. When the other player then joins the map, my units start instantly moving to their commandpoints and often the minimap shows this:


This behavior happens, after i had to refresh/clear cache/new ip, because i was stucked on coop loading screen.

Maybe you can have an look.