I had an issue once, one time out of so many I can’t count. Was worried for a minute but nothing ever came from it. Got a letter from the United States Postal Inspection Service, Criminal Investigations Center. Said my item was being withheld from delivery because there are reasonable grounds to believe it’s contents are nonmailable , hazardous, restricted and perishable mail. Gave a number to call if you wanted to discuss or provide evidence that the mail doesn’t contain nonmailable items, also said you could appeal the determination.
I’ve learnt to ignore shit and most times it will go away, if you act on it, try to sugarcoat it or cover it up more it’ll usually bite you in the ass.