I tried another config from last hour and is worrking good:

Old drivers uninstalled with DDU (I was using 20.2.2 or something, can't remember really)

Sapphire RX6800 Pulse, Samsung mem.

681 mV CORE
1200 Mhz CORE (1192 real)
2150 Mhz VRAM (2138 real)
21.2.3 DRIVERS
125W
63,8 MH/s
1 stale last hour.