https://github.com/Z-Bolt/OctoScreen/blob/master/debian/control#L21
The debian package depends on x11-xserver-utils, please add it to the dependencies in the package control file.
Nov 14 12:55:25 octopi bash[2675]: /etc/octoscreen/disablescreenblank.sh: line 8: /usr/bin/xset: No such file or directory
There are several closed issues that have this error in the posted logs with exactly the same issue, the ui is switching back to tty0 restarting the X window.