Then I've figured the Gerrit has pushed my new commit under /ref/tags/ovirt-engine-3.6 rather than ovirt-engine-3.6.1 branch, so CI doesn't run on that nor it could be merged.
Needless to say that I didn't meant to push a change to ovirt-engine-3.6.1 tag and chose the branch from the list that UI offered to me and that appeared as "ovirt-engine-3.6.1" in the UI.
Today I've cherry-picked the patch manually and this worked as expected.
IMHO Gerrit should be configured in the way that prevents such mistakes, either by filtering out tags from the offered list or by not using branch names as tags.