I'm trying to update my Mavic 2 Pro to the latest firmware, the 200 version.  I got the controller to 100% twice this morning using DJI Assistant 2 1.2.4.  It said that the update finished both times that I attempted, and a button appeared on the upper right corner of the window that said "Back".  When returning to the list of versions screen, the version said it hadn't yet been updated to the 200 version.

EDIT: Somehow I've successfully updated the firmware of the controller using the DJI Go 4 app.  I'm still having the trouble with the AC though

For my AC, I've reached 99% completion twice, and both times the progress halts and I get the "update Failed" message.

I've tried using the DJI Go 4 app, with my galaxy s8, and instantly it says network problems.

Hi there, sorry for the inconvenience caused. Just to clarify, have you tried to update the firmware of your Aircraft via DJI Assistant 2? Please make sure to connect your Aircraft at the PC first before you turn it on. If the issue persists, please try to uninstall and reinstall DJI Assistant 2 or you may try to use different PC. You may refer to the attached video tutorial below. Thank you.

Could not update firmware for Mavic 2 Pro neither from DJI GO 4 app, nor from DJI Assistant 2 for Mavic. This is a problem that has been existent for months now!!! Last resort to try from an Apple device because I've read that some people had success only by updating through an iPad...which is absurd to say the least. Sort your stuff out, DJI!

I was able to update the aircraft via DJI Assistant but did have the same experience as you updating the controller. It did update through DGI GO flawlessly. Ist time the Assistant failed for me.....

I got the AC to update with your suggestion, Thanks!

For me, RC updated on it's own. AC was a different story.
It kept stopping saying to restart and try again. Then I connected it to computer and DJI assistant accomplished it first time.
Haven't flown yet to see if any different.
(Personally, I could care less about precision landing. I always manually land.)