I'm having this issue with my Samsung 10+ as well after the recent update. I tried clearing the cache and restarting, but the individual notes still won't open.
I'm having the same issue as well, I have the S10+ and since the recent update my notes are all blank when I try to open them, and the app crashes if I try to get out.
The app crashes when I tap the cog button to try the fix you described.
I have the same issue as the comment below when I open the app, i am able to see the notes i have saved, but when I try to open the individual note, it appears blank and then the app crashes.
I tried updating my app yesterday but there wasn't an update available, I went back in this morning and now there is an update and it fixed my problem, so thank you for the help!
Have you tried updating the app? This happened to me and I read a lot of posts explaining that the app needs to be updated. The problem is, the app wouldn't give me the chance because it kept freezing, so I updated through the Google Play store. Try that!