Yep, I might also mention I had success in June of this year in FRA at both the Term B lounge and the Term C lounge with similar situation. Wife(guest) and I on LH metal using my PC paid membership card.

I can only think of two answers: 1) Policy change from June to December or 2)MUC LH Agents were incorrectly trained on paid membership card access to LH Lounges.

Got my fingers crossed for Fri flight.

ps... That printed OnePass Gold card from the CO website got me no where. They wanted hard plastic.