I've installed 19.9.3 drivers and switched back to PM 4.7b from claymore's miner, now mixed rig is working flawlessly, thank you @PhoenixMiner. BTW claymore's miner consumed 10 watts less and hashrate was just 0.8 MH/s lower for RX 5700.
Any significant improvements?
For me PM always was better, but previous version was unstable with 19.9.1 drivers and with 19.9.2 didn't work at all. Now it looks like stability problem solved, however i see one reboot during last night. Also i've noticed that 5700 card after some time begins to give +2 Mh/s, but after dag switching this speedup is gone and again after some time miner shows +2Mh/s until dag switch.