I have 1 code repo that should be triggering jobs, and a separate repo for a jenkins pipeline library. There are 2 jenkins jobs that use the ‘GitHub hook trigger for GITScm polling’ build trigger, both are pipeline jobs using the ‘Pipeline script from SCM’ with the repository configured to point to the code repo and the ‘Branches to build’ set to ‘origin/develop’. The pipeline library is used inside the pipelines for these jobs.
I would expect these jobs to have their polling triggered by pushes to the code repo, however they are only being triggered by pushes to the jenkins pipeline library repo.

Using a log recorder set to get FINEST logs I can see:
Received PushEvent for https://github.com/<code repo>
Considering to poke <job>
Skipped <job> because it doesn't have a matching repository.
...
Received PushEvent for https://github.com/<pipeline library repo>
Considering to poke <job>
Poked <job>

So something in jenkins seems to think these jobs do not use the code repository, but when a scan is triggered I see the following in the ‘Polling Log’:
Started by event from 192.30.252.97
...
> git ls-remote -h https://github.com/<code repo> # timeout=10
So the repo poll is using the code repo, and the list of commits that show up in the ‘Changes’ list are from the code repo.
It seems to be only these 2 jobs that are affected, no other job is being triggered by pushes to the pipeline library repo.

If I change the job to have the pipeline script entered directly and clone the repo as part of the pipeline it is triggered by the webhook correctly.

I was able to work around this using the poll scm trigger which will run the job correctly.