The owner of this hotel which runs it as a Hyatt House has declared insolvency last week in Berlin. In court, the filed for a restructuring under their own supervision.

It seems likely the HH will keep operating short-term, but I'd strongly advise against booking any prepaid rates there.

Revo also manages a bunch of Accor/Hilton/Wyndham/Moevenpick franchises. The Accor and Moevenpick properties have stopped accepting booking. From what I can see, Hilton/Hyatt/IHG/Wyndham properties are still bookable (only tested for a sample).