Ok, so Vega64, on V4 algo, right?
Are you using text config file or cmd ?
Please paste it here.
If there was such a bug in miner i guess others would also report

Correct. 64 on v4.
I've just changed my wallet at pools.txt, everything else is stock. What is weird, because this is working with 1.8.1. But for some reason 1.8.2 breings only 1100Hs, instead of 2000+.