Yeah, deffo on the pool side something is not ok. Forgot to tell you that CPU miner worked fine, did not lose the connection - the LucasJones 1.3 (cause of my CPU which doesn't support AES)... Now it also started to loose connection. Though it connects instantly after starting it. As for GPU miner, it was connected all the time (or it reconnected but I didn't see it) but hash-rate is below the max value where it should sit. GPU utilization is fine - 99%... As CPU's.

Also I tried to mine XMR, and from a start I get some sub-max hash-rate which is very close to the max value as it should be... Ofc, I am connected almost instantly when I start the miner. Everything worked flawlesly for me till today. Maybe I'm an isolated case.