I have reproduced this issue, and have posted and update that should fix it. Please try downloading either of the demos again and let me know if it still gives you issues.
I have received a few reports on Linux. I'm working on it. Literally this is the reason why jDeploy is helpful. I've spent 2 years working out many details. Every OS/Version/distribution has needed some special care. Up to now I've been working with a single Ubuntu 20 box for my linux testing. Today, in response to these reports, I'm setting up a number of Linux VMs to test other variations to get to the bottom of this. I should have these issues resolved shortly.