The installer is less broken than before but still broken: no URL opens

I installed Prey 1.9.10 (on Linux Mint, which I know is not supported officially, but I’d be surprised were this bug either not to affect Ubuntu or at least not be the result of a mistake in the code). Everything worked - though goodness the installation takes an age on older computers - except that when the browser (Firefox) opened, no URL was loaded. I take it that an URL is meant to be loaded. (For, otherwise, the action is pointless and looks like a bug.)

Also: since I’ve installed the new Prey, I’ve had screen corruption and this error in the syslog: ‘linux bamfdaemon: Fatal IO error 11 (Resource temporarily unavailable) on X server screen corruption’. That conjunction could be a coincidence . .

The screen corruption was not caused by Prey, I find.

Also: when doing a fresh install, the browser opened at the correct page. But . . in so doing it somehow managed the browser:
2021-04-14_19-10

Note the doubled title bar (and my Firefox does not usually look like that).

Prey product support people: are you engaging with these problems, please?