Thank you for your support all this while. The issue is now fixed in the latest update of InDesign.
Please upgrade to the new InDesign 14.0 from your Creative Cloud Application.
If you are unable to see the update yet, click on the menu (three dots) on the top right corner of Creative cloud app and click on “Check for App Updates”.
Let us know your feedback in the comment section.
InDesign TeamKim commented
Indesign 14.0.1 is broken. When I try to change a font in the font-window, InDesign freezes and I have to restart!!! Please fix this ASAP!!!