1. Changed my Text Note "automatic read-only" size to 2000 characters
2. Pasted something like 1950 characters, saved+refreshed
3. Type characters past the automatic read-only limit (to something like 2050 characters)

If you keep typing within the Note after this happens, all of your changes are lost since the "bug" happened (and shows duplicated text).

If you have many white spaces while editing, you might not even notice this issue even happening.