OpenCore and FCP? Version after version...

Hello guys. I've got this perplexing problem I can't figure out.

I'm running Martin Lo's OpenCore on my 5,1 cMP with Catalina. It's been working great...until I want to install and open FCP.

I've installed 10.5.1. It opens. Functions fine. I re-start the machine. No longer opens. Nothing. Dead.

Then, I install 10.5.0. Nothing. Same.

I install 10.4.10. Nothing once again. Dead click. No errors...no popups...just nothing.

I install 10.4.8. Success. Works like it should. Same story for 10.4.9. Perfect.

Any thoughts on what's going on here? It sort of worries me as I have a few projects saved in the latest version...and you know what that means. The only way to have 10.5.1 open again is to restore from a TM backup...re-install FCP, and not dare to re-start the machine...which really isn't the most effective solution.

Thanks a bunch folks.

What are you using OpenCore for? I'm just curious.

A few reasons. One is to run Catalina on this 5,1 machine (without patching it with dosdude's patch). Second, to run a non-EFI GPU card with the Mac OS so that it boots. Works out well...except for this danged FCP opening issue.