The notify your team after uploading a file to SharePoint feature is not working for guest users. When a guest user clicks on notify team they are able to use the people picker and select a user. But as soon as they have selected a user to notify they receive a "Sorry, you don't have access" message. They don't even get a chance to press the notify button.
If you try to do the same thing with a licenced user it works fine and they are able to notify a user after uploading a file.
Is this expected when guest users try to notify other users? I have tested this on a few SharePoint sites in different tenants and the results are the same.
I have a guest user who says this has been working fine until recently.