Any news on this issue? It still persists on the latest Firefox, WordPress and ACF.
Delaying the initialization of TinyMCE helps, but that isn’t wanted for every field/site/client. It’s a work-around at best.
There is no clear Javascript error shown, though the problem almost has to lie in the Javascript code somehow.
It happens on all WordPress admin environments that use ACF, with Firefox, so it’s not specific to any host or another plugin.
Please ACF devs, can you at least reply to this issue? It’s been years.
