My virtual memory is NUMBER_OF_GPUS * 8 + 8 GB. And on 19.4.3 all works. Miner didn't support new AMD-APP in 19.5.x drivers. And he wrote about that right after launch.
Did you see any improvements over 19.3.3 with 19.4.3? I was using 19.5.2 on claymore and switch to Phoenix and it was working but got an error on start up about unknown openCL and I had one card would fail after a few hours. I switched to 19.3.3 and now its rock solid.
Rig : 2 MSI RX 570 4GB and 4 MSI RX570 8GB . 184.2MH/s