I have Pipepipe working as well.
There is something a bit off about it. When I try to import the show list that I have subbed, NewPipe is throwing an error that the file exported PIpepipe has some sort of 'unsecure" feature in use. I forgot the exact error though.
Otherwise it works. I wonder if it has some sort of shenanigans happenning, not necessarily by the side of the devs… more like misconfiguration? What makes me think is that Google isnt blocking it… maybe we are leaking some sort of indentifying information?