I have the same issue, both on wasteland as well as most other missions. However, it didn't start happening until I played wasteland 1.05

I have this issue to, but not for 30 secs - 20 mins.

I also have the same issue when scrolling far down on servers with many slots

I found another issue report about the same issue and suggests that this has something to do with thomson routers which is what I have. That is most likley the problem

It seems like forwarding ports 2302-2307 or whatever ports arma uses solved my issue. There will be a problem if 2 people behind the same router want to play though

I also have the same problem on a thomson router. I have disabled upnp which caused similar problems in BF3 but no luck