is a known with the nvidia’s own branch, I have fixes for it (I should probably just rename the branch to 4.19-FleX as it doesn’t look like Nvidia is merging my PR for the fixes):
https://github//UnrealEngi…PR-FleX-4.19.2
Actual PR : /pull/523
Basically you can just use that PR-FleX-4.19.2 branch as is, it only contains UE 4.19.2 and Nvidia FleX or alternatively copy the fixes over manually, all changes are in 3 commits.