Pipeline moved on before job finshed and sets pipeline to failed (even though no error)

Summary:
Our pipeline emails are showing as failed if a job is still running when it ends. It is also moving onto the next job rather than waiting for the job to finish.

Content (please ensure you mask any confidential information):

If a job takes longer than around 30 mins in a pipeline, it will move onto the next job before finishing.

It will also show as "Running" in the pipeline email and the email will say the pipeline has failed, even though when we check the job console, none of the jobs in the pipeline had failed.

Is this the expected behaviour? Surely the whole point of pipelines is that the jobs run in sequence, so they should wait until the job has finished before moving on.