Network Settings > Enable administration menus > plugins stays checked

In mulitisite where im testing wpmudev plugins, on local, I have main site & one more site.
I'm seeing same issue as another person asked before
here on forum.

I cant uncheck the option from the title and save it.

Since multisite is what wpmudev is mostly about, I presume there should be some knowledge of this issue.

I tried disabling all plugins on all sites - except those mu-plugins by wpmudev, like
gateway relay and wpmu assist.

I enabled WP_DEBUG, theres no clues in log files.

Other options save ok.

Im not sure, but when I try to save it, it seems like the form option doesnt even get sent, cause I tried inspecting the POST parameters.

Froom googling, I saw another person here had the same issue, thats the link I pasted.