When you moved the tape into a production media set after labeling it, it took on all properties of that media set including OPP as of the time that it was moved. Thus for a 14 day OPP, you cannot use that tape for 14 more days.
It may be a bit of a pain to set up, but you could create 21partitions (virtual tape drives) in your loader, and alter the jobs to point to the appropriate partition
Or for the next 21 days, you could just move each appropriate tape volume to the scratch media set before you go home for the evening. After that, the rrotation ought to work automatically