Indeed many of the useful posts here are 5 years or more old. It’s been very quiet over the intervening years on the forum.
I linked that post to get things started for you. Hopefully others with similar setups to yourself will join in with some useful advice.
While your unit is recognised it may need additional firmware installed to function correctly as can be seen from here. https://www.linuxtv.org/wiki/index.php/Xbox_One_Digital_TV_Tuner
You could also try asking over at the Raspberry Pi forum if no further help is forthcoming here.