Few more hours of testing and I think I have found another problem (or maybe it's just happening to me). WiFi connection download speed is very low. With stock averge was 1,15MB/s with strongest signal and now it's somewhere around 300KB/s (basing on downloads from Play Store).
After few tests it turned out that the problem wasn't caused by rom or router. There was a problem on network provider side. Sorry for false alarm.
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