"Add People" feature for Notes on my MacOS does not work

Anytime I attempt to add a people for collaboration on a given "Note", I don't get asked about adding people and I I get an error message "Sorry your information could not be sent". I am on MacOS 10.13 and up to date on all software updates. Any ideas, please?

I am having similar issue on my iPhone as well where the button "add people" on some of the Notes is even missing and on those with the button, I get an error message "Could not connect. There may be a problem with the server. Please try again later."