Same issue here, playing from Russia.
First one or two minutes since server join my latency is absolutely fine (about 100-120 ms), then everything goes crazy (latency increases and stays around 15-30 seconds).
Here is a screenshot with debugging information (not sure if it’ll help, just bought the game and don’t know how can I give you more info on this):
My rig is equipped with i7-2630QM (on High Performance plan, that’s about 2.8 GHz as far as I remember) and Radeon 6770m.
I switched almost all graphics options to low, set FPS cap to 30 and getting stable FPS, so looks like it isn’t a performance issue.
The stable branch is working fine.
EDIT:
Found a post about similar problem:
I’ll try to log into game again, maybe it’ll be gone now.