Weird issues with debian-core template from liteqube package

The debian-core itself starts up properly, but any VM based on the template ends up non-functional with xvda / filesystem mounted r/o. I could not find out what happened there, but remounting it rw early in the boot does not help either – qrexec agent does not work at all. Nothing suspicious in logs, systemctl status says the system is healthy. Anyone here got it running with 4.1.1?