Actions fail to run on additional commits after PR is created

I have some actions configured for running tests against my codebase on every push. After creating a PR for a given branch, the actions ran and exposed an issue via a failing test. After making the necessary fixes and pushing another commit, the actions will no longer run. I’ve tried making multiple additional commits to see if I could trigger  them, but no luck. 

This is the trigger mechanism as defined in my action:

on:
  push:
    paths:
      - 'back/*'
      - 'ops/*'
      - '.github/workflows/*'

Besides the fact this appears to be some sort of bug, it’d be super helpful if there were a way to trigger the actions for a given commit SHA. If I go into Actions and view the failed run, there is a button to “Re-run all checks” but unfortunately that will only rerun the checks for the same commit/SHA they originally ran against, and not the latest on the branch. 

I went ahead and merged the PR into master anyways, and actions started running again. Thoughts?

Is this possibly because the push trigger gets overridden by pull_request w/ the synchronize type somehow? I’d expect both to trigger the actions, but perhaps not?