FCP 10.4.8 work with OS 10.15.2

I haven't used this forum for years sorry. I downloaded my iMac to Catalina 10.15.2 running FCPX 10.4.8 and upgraded several projects only to find they constantly get the spinning wheel. I know years ago you were supposed to wait on updates, now what can I do to get the project running smooth?

iMac late 2015, 16GB ram, AMD Radeon R9 M395 2 GB

Thanks for any help....Rick