Hello
I'm having a "coming and going" issue with a certain workflow where from time to time I, and others, seem to lose the ability to transition issues correctly.
Below you can see my workflow:

Transitioning from NEW to WORK IN PROGRESS works and normally the WIP to RESOLVED transition works fine too. Sometimes the workflow seems to develop a bug of some kind where the only available transition when in WIP status is PENDING.
Now I just faced this issue again today and tried to transition from WIP to PENDING status and this is what happened:
When I clicked to confirm PENDING status, the issue by itself moved to WIP and then to RESOLVED. I'm baffled by this.
I should say that I have full admin rights in the environment and the affected project and that there have been no changes made since the workflow was last functioning. There are also no conditions in the "Resolve" transition:

I have successfully fixed this issue twice before by copying the workflow and moving all issues to the new workflow. It's obviously identical but works like a charm. That task is a nuisance though and I would not want to continue doing it as I'm sure this is not the way JIRA is intended to work.
If you have any suggestions in how to fix this, please do share!
EDIT:
I want to add something: Currently the issue is causing another weird "bug", if you can call it that, where the resolved issues remain in the "All open" (issues) default search view. I gathered so much, that it's because the "Resolution" field is left "Unresolved" when the issue is not properly transitioned to RESOLVED. In the transition I've added a screen that requires the "Resolution" info. Also there was one instance where an issue had moved to CLOSED status after RESOLVED status, even when there is no such status in that workflow.