Today in the MUX-3 in digital terrestrial television (in standard: DVB-T) in Poland, the channel: TVP Sport (SD) has started. The TVP Rozrywka channel (MUX-3) has been removed from digital terrestrial television.
The TVP plans to launch the TVP Sport channel in the HD version of digital terrestrial television most likely on MUX-8, and it depends on the TVP negotiations with Emitel (probably the equivalent of your Zeonbud) regarding the price for entering on this MUX and broadcasting there. Negotiations began at the end of April this year.
Of course, most probably, in addition to this channel, other TVP channels would broadcast on MUX-8, such as perhaps again in terrestrial digital TV: TVP Rozrywka.
TVP in MUX-8 can put two channels: one in HD and the other in SD or: three SD channels.
Work is in progress on the transition to Full HD channels of the Regional TVP3 channels (most likely ending with the end of 2019 or 2020). I think there is a high probability that in such a quality the channel will appear on MUX-3.