Gigabyte AB-350 Gaming 3 is 100% stable up-to 3600Mhz for me on 1gen Ryzen 1700, and I can test and fiddle around 3800Mhz all day long now.
Though I never found something work in the length for that speed(3800) without errors but you can use the computer/game whatever(at your own risk))
The newest Agesa 184.108.40.206 improved stability at above 3600Mhz-->3800 but the previous 220.127.116.11 worked up to 3733Mhz(3800 was unusable but bootable).
Now you can use 3800Mhz but I can never squash these pesky few errors at times with TestMem5. I think it's CPU-IMC side as SoC voltage plays a large role on it.
Gigabyte X570 AORUS XTREME, Ryzen 7 3800X 4.45Ghz, 4266/1900 MEM/FCLK, 18.104.22.168.76.tRFC 650 1T 1.58V
4x8Gb Kingston HX434C19FB2K2/16 3466C19 1.2V (Micron E-die 16nm)
OLD: Biostar x470GT8 Ryzen 7 1700 @ ~4.0Ghz CPU, 3200Mhz RAM ...