When an event occur on a change having Code-review +2, it is enqueued in gate-and-submit and would eventually be submitted in Gerrit.
On the operations/puppet that means such a change would not have any test run again for example when doing a rebase. An example is https://gerrit.wikimedia.org/r/#/c/operations/puppet/+/509888/
Patchset 2 got a Code-Review +2, the rebase had the vote sticking which filters it out from the test-prio pipeline.
The workaround is to remove the Code-Review +2 label and recheck.