I see that you’ve obviously previously set the Track 8 to be a Flex assigned to RecBuffer 8 and then changed it to a master in order to have access to the buffer in the editor as it’s otherwise not possible to get the waveform up
however, I suspect the issue is that there’s (sort of) no machine on the track to play the audio back, or more likely this usage scenario wasn’t catered for - it’s a quirk for sure, it’s actually quite handy that the record track on Master 8 still works, so I agree it’s a pity that the buffer doesn’t play (for whatever reason) - it may be worth flagging this up, but I suspect it may be supposed to act the way a neighbour track does when you pre-arm with its respective buffer and have a recorder active, in this case the editor waveform simply displays n/a
something’s a little inconsistent somewhere for sure