I am on 10.13.6 and use KeePassXC just fine, although I do build it from source, so that probably explains our different experiences. I just wanted to chime in

I am on 10.13.6 and use KeePassXC just fine, although I do build it from source, so that probably explains our different experiences. I just wanted to chime in that the accurate statement seems to be the prebuild dmg from them fails to run on < 10.15