In the Notes that are a part of a Contact card-I am not able to @mention anyone who has access to that specific lead pipeline. I have tried different pipelines and in all cases it states that nobody has the ability to be mentioned. I am wondering if there is a general setting we need activated for this? All @mentions work in processes, leads, and inbox as expected but this is not working within the Contact card Notes.

based on a support request: I followed up with he team on this, and the notes feature for contacts is something that was released with the Maintenance product.

This feature was meant to leave notes related to the contact, but was not designed for users to be able to tag each other. Due to this, if you would like to have the ability to tag other users on your contact's notes, this will need to be a feature request.