Thank you for the quick response Steven
Here's what I did so far:
1- Cleared the audiobooks from MusicBee
2- Added one m4b audiobook from a local drive
Result: No Change, file shows up as a single track (no chapters) and time shows up in min:sec
3- I uninstalled MusicBee completely, then deleted MusicBee folder under C:\AppData\Roaming and C:\Program Files (x86)
4- Reinstalled MusicBee 3.1
5- Added same m4b audiobook again.
Result: for some reason, this was added to the music tab, and I wasn't able to drag+drop, perhaps due to loss of my preferences.
Time shows up in hr:min:sec (yay!
Still shows up as a single track (no chapters)
6- Just to check, I dropped the same m4b file into Chapter and Verse to make sure it does have chapters, C&V showed 72 chapters in the audiobook. If there's a preference in MusicBee that makes chapters show up, I can't find it.