bug notes
extra bit of data that might be helpful.
I was having this happen, and restarting bspwm didn't fix it.
so I disabled the line in my bspwmrc that loads the bspwm.json and then restarting *did* work.
bspc wm -l ~/.local/run/bspwm.json
so likely, the bug could get reproduced and tested given an appropriate json file to load.