This is a packaging spec issue that affects to openstack-manila-ui Rocky release. Manila python files installed in: /usr/share/openstack-dashboard/openstack_dashboard/local/enabled are only accessible by root (-rw-r-----) so apache is not able to access them and the Shares Tab does not appear from the OpenStack Dashboard. The workaround is to execute chmod +r to fix the manila panel files. It seems that this issue only affects to the share tabs.
This issue is related with: https://bugs.launchpad.net/manila/+bug/1809309
*** This bug has been marked as a duplicate of bug 1661395 ***