Booking the night train from Munich to Krakow

Hi, looking for some advice! I would like to take the night train from Munich to Krakow in July, but I haven’t been able to find any tickets yet. I checked for July 18th, though I could also shift the departure date by a couple of days. Does anyone know how far in advance tickets for this train are usually available? Or could there be another issue? On the ÖBB website it says “currently not reservable”, which might be due to construction work or missing timetable information. I would also appreciate hearing from anyone who has already taken this train. What was your experience like? Would you recommend it as a first night train trip? Thanks in advance!