My setup is behaving exactly the same as yours on my Atom. I run BubbleUPnP Server on my QNAP NAS and do not convert to WAV.
Interestingly, playing the same Qobuz album on the Auralic streamer in my lounge system using Kazoo or Lumin as control points does display the KB value, but that streamer is an OpenHome renderer and does not need Bubble.
Do report back if updating your FFMpeg libraries makes a difference.
No, I just used the default settings. My Atom is on FW 3.5 and I can’t remember whether I had the issue on 3.4. One slightly odd thing the FW upgrade did was to rename my device by adding some numbers (probably serial number) which broke the link with Bubble. At first I was puzzled why Kazoo and Lumin could no longer see the Atom until eventually the penny dropped and I sorted the problem.
TBH I use the Naim app nearly all the time so it’s not really an issue for me. The one advantage of Kazoo is that I can run it on my iMac and control the Atom on my desk without needing to find my phone.
Work Around…If I transcode to WAV via BubbleUPnP server then I see the correct bitrate for the Qobuz file along with sample rate and bit depth.
It just doesn’t work for FLAC without transcoding. It could well still be something to do with the ffmpeg binaries but it’s not necessarily straight forward to update on my version of RPi so have left for now. I did try updating the ffmpeg binaries on my Mac but it made no difference. Might come back to it in future.