The typical source of “works in debug build but not in release build” problems is uninitialised variables. In debug builds the memory has been zeroed, in release builds it has not. That usually leads to crashes in the release build, which appears to be what is happening here, but in a thread so not bringing the whole program down.
I was going to suggest contacting the plugin author, but I looked it up and the most recent version of UE it is available for is 5.0, so I am guessing they aren’t working on it anymore and it is maybe not surprising it doesn’t work in 5.4.4 