Hi Abhimanyu,
since you are facing issue with only one field in production, then certainly there should be some non-printable chars present in data.
how did you loaded the same record in Dev? copy and added it to PSA and ran dtp? my point is if there was a TAB in the error record which may display as #, when you copy, it might just treat it as a # and that is the reason it got loaded in Dev?
we faced a similar issue earlier, below blog might help you.