[Hanging on startup?]

Clarification to this - it looks like the app does (eventually) start, but seems to hang for several minutes first...

[Hanging on startup?]

I have just installed the latest version of CCleaner for macOS (1.18) on a Mac Laptop running Catalina (10.15.7), but unfortunatley CCleaner is stubbornly refusing to start - I see a spinner and then nothing more; the only thing I can do is to Force Quit the app. I'm aware of the problems with Catalina in general and have tried the usual tricks of right-clicking and selecting "Open" under Applications, as well as checking for Gatekeeper issues in "Security & Privacy | Allowed app", but am seeing nothing listed.

Is there any way I can diagnose what's wrong? I've tried launching from the CLI, but same problem and no additional output...

Thoughts?