I recently submitted a preprint to arXiv, and it has now been "on hold" for 3 weeks. There is nothing obvious wrong or questionable with the paper in my view, and I have around 20 of other arXiv preprints.
I have not experienced any delays like this before (once or twice there has been a delay of 1-2 days). After 10 days, I used the arXiv form to contact the moderators who told me that the moderators have been informed that my submission still needs a decision (and that they can't give me any exact reason for why the paper is on hold), but nothing has happened in the 10 days since.
Are these extreme delays common, and what should I do? Can I just delete the submission and submit it again (the rules on the "on hold" help page only state that one should not submit the same paper again while it is on hold, but don't mention the case of deleting the old submission).