To add to the growing list of users experiencing this issue, we are in the same boat. The crashes are very frequent, sometimes occurring only after a few minutes of opening the editor and moving the mouse around. And the crashes only occur in 5.5.x. Because the crashes are so frequent, our workflow efficiency has been hindered immensely. Many days we’ll experience 40+ crashes in a single day. 
The error is the same every time:
LogWindows: Error: appError called: Assertion failed: UnderlyingResource->GetRefCount() == 1 [File:D:\build++UE5\Sync\Engine\Source\Runtime\D3D12RHI\Private\D3D12Resources.cpp] [Line: 1313]
I have opened a UDN ticket on this today in the hopes they can provide a fix or workaround.