I had the same issue with my MacbookPro running BigSur 11.0.1 and Evernote v 10.4.4 build 458403.
When I shut down my computer and restarted it everything finally started to appear again. Restarting Evernote did not help. Restarting my computer and then launching Evernote resolved this problem for me.
[Troubleshooting] All notes appear as blank in Evernote
in Evernote for Mac Issues (Versions 10.0 and above)
Posted
I had the same issue with my MacbookPro running BigSur 11.0.1 and Evernote v 10.4.4 build 458403.
When I shut down my computer and restarted it everything finally started to appear again. Restarting Evernote did not help. Restarting my computer and then launching Evernote resolved this problem for me.