This report does not specify the exact URL that was used for the snippet generator. I tried /pipeline-syntax/, /job/pipeline/pipeline-syntax/, and /job/multibranch-pipeline/pipeline-syntax/ and none showed the behavior reported. Jenkins 2.107.3 from docker image, newly set up with current Matrix Auth and Pipeline plugins during setup. Does not exhibit problem reported.
My guess is some hackery in the pipeline snippet generator causes this with plugins that aren't prepared to have their config form shown without a corresponding job property instance. Unclear what's going on there.
The reason this is my guess is that my in the Groovy view would need to be empty, and when I tried to reproduce this, I instead got a list of job properties, and…
WARNING: Caught exception evaluating: descriptor.isOwnerMultibranch(it) in /$stapler/bound/0f6b827e-8025-4054-a40d-5d658e80be5f/render. Reason: java.lang.NullPointerException