Indeed, as I stated in the other topic to our beta testers, the Apple betas are usually quite a ride, with some issues appearing out of nowhere, only to be fixed by Apple a release or two later. We’re only at the 2nd developer beta, and the 1st public one, so there’s still quite some time before it’s released (probably around 3 months).
Even if those betas are public, it is always recommended that you not install this over your main OS. You should make a partition to install it separately (which is made even easier now with APFS), and just install those for curiosity’s sake and not actual work, otherwise you’ll probably lose quite some time with such issues.
That being said, this issue has been reported and we’re in the process of fixing it, but please understand that while that fix may be released soon on the beta versions of PhotoLab, it may be some time before we release an update to PhotoLab 2 to fix this issue, as Catalina is still quite far from being released, and it wouldn’t be reasonable for us to focus on this instead of working on new features for you guys.