Basset, to my knowledge this is the only Hilton hotel in Poland which has done this with its lounge. Krakow & Wroclaw are open, both DoubleTree. Warsaw (Hilton) Gryzbowska is offering the lounge benefit at the bar, though the food side is reduced.

Perhaps the rates will have gone down since you made your Advance Purchase booking and even if you considered coming back you might save money booking the fully flex rates now on offer. You might try the Hilton form for Covid refunds on the website when you choose Contact Us.