Provisioning stopped working after upgrade to 27.0.4

Blocking problem:

Adding service definitions in Provisioning has no effect on the node. New service is added in Provisioning, but node is not provisioned.

History:

A standalone OpenNMS installation monitoring ~100 nodes and ~1.000 services has been upgraded from 26.2.2 to 27.0.4.

Apt packages were used from the OpenNMS repo,  the upgrade didn't show any errors or warnings, /usr/share/opennms/bin/install -dis was executed.

After some hours of running it has been discovered that new services couldn't be added to or removed from existing nodes.

New nodes could be added, also discovery found new nodes.

The proposal in OpenNMS chat of executing 

service opennms stop; yes /usr/share/opennms/bin/fix-karaf-setup.sh; service opennms start

didn't have an influence on the problem.

If I can provide any files or additional input, please let me know and I can share. 

Thank you for the support!