Hey,
we also encountered a memory leak that seems to be caused by viewport rendering, also in packaged games (but we didn’t test shipping builds). Can you please add the following line to your DefaultEngine.ini file and see if it’s still leaking (preferably under RendererSettings)?
r.gpucrash.collectionenable=0
It seems to be important to add this line to the ini and not enter it at runtime.
I guess this is not a fix, but it can help narrow the issue down and maybe help epic fix the issue properly.
sirjofri