I've found the fix on an older post on this forum!
- from the web version change the default notebook to another
- close and reopen evernote Android, now you can save with success!
- from web version change default notebook to preferred
If you delete the data of the app, you have to repeat steps above.
The little problem that persists is that you see more than one 'default notebook' under notebooks, thats's only grafical issue, app works normally.