Problem could not be reproduced, because it was hidden by bug #1795774.
After installation from proposed, the problem was solved:
root@gert-laptop:/etc/apt# dpkg -s libmutter-2-0 | grep Version Version: 3.28.3+git20190124-0ubuntu18.04.2
Problem could not be reproduced, because it was hidden by bug #1795774.
After installation from proposed, the problem was solved:
root@gert- laptop: /etc/apt# dpkg -s libmutter-2-0 | grep Version git20190124- 0ubuntu18. 04.2
Version: 3.28.3+