Can't change the font in Mogrt in After Effects

Turn off the cloud-based Adobe fonts and see if it makes a difference. This apepars to be an issue where the dialogs are continually refreshed due to a bad connection. Also of course the usual: Disable/ delete any unused fonts in the first place to make the list shorter and more usable and definitely weed out any shady "bad" fonts you may have downloaded and added lately.

Mylenium