BUG? - Suddenly unable to use $CI_PIPELINE_IID in workflow.name

Hey,

For a long time we've been using:

workflow:
  name: $CI_PIPELINE_IID - $CI_COMMIT_TITLE

in our pipleines. This was working until yesterday, at some point between 13:00:15 and 15:23:08 Central European time when $CI_PIPELINE_IID began interpolating as an empty string:

We made no changes to the pipeline definition between these two runs. Any idea if there was a release around that time that could have been responsible? or some way it could be on our side?

Many thanks