Heya
With RE3 I've never been able to launch it in DX12 on my Vega56. Well I only tried once but it had a crash issue after applying the setting and restarting for it to take effect. To fix it it had to go to the game folder and open the "re3_config.cfg"
"steamapps\common\RE3\re3_config.cfg"
and change 2 settings back to DX11 to make the game launch again.
If you are using Windows 10 leave this setting as "Capability=DirectX12" since you are compatiable
but change these 2 settings to "DirectX11"
"TargetPlatform=DirectX11"
"PCDXver=DirectX11"
Hope this helps
Might if you where last playing in DirectX12 before getting your new card