Yes, thank you ctt! I did not find this gem during my forum search. The "fix" worked like a charm. I am copying the relevant instructions here for others in this jam:
"1) Please Download The DJI Assistant 2 application, which can be located in the Mavic Pro Download Section. Download your current computer manufacture.
2) Once you Log into the program, please connect your defective battery into your done (Please disconnect its Gimbal Protection & Propellers just in-case) & let it initialise.
3) When the drone is booted up, connect your controller to your computer via the USB that came with the Mavic. Then, turn it on (otherwise it'll just remain in a charging state).
4) Your computer will install its relevant drivers automatically (Leave it for 1 minute).
5) Then, you will get an option to select your drone. Please do so!
6) A list will come up with all current Firmware releases from DJI, select the most up-to-date firmware & click "refresh".
7) Let the program do it's business downloading & installing. At the very end your drone will reboot along with your controller. Please don't worry if you lose connection to the program it'll return by itself!"
And thank you fans3078e08b for the instructional post!