Sorry, that username already exists!

I’m trying to Add User (after already deleting them – more info below) in the network admin and I am getting:

Sorry, that username already exists!

That username is currently reserved but may be available in a couple of days.

Sorry, that email address is already used!

That email address has already been used. Please check your inbox for an activation email. It will become available in a couple of days if you do nothing.

The users is not showing in the ‘All Users’ lists on the network admin site or any of the sub-domain sites.

I have a multisite network.
I already previously added the user (I can’t remember if I did this from the network admin ‘Add User’ or a specific sub-domain sites ‘Add User’ sorry). The user was sent an activate account link, but the accidentally deleted it before clicking the link.
I then deleted the user.
I am now trying to add them again but am getting the issues I mentioned above.

Looking in mySQL I can see the user name is under wp_users (with a user_registered date, no user_activation_key, a user_status of 0 and deleted set to 0). It is also under wp_signups (with a registered date set, activated date set to the same, active flag set to 1 and an activation_key)

Any idea how I can get this user set up again? I don’t want to wait a few days for it to become available again (which I don’t think it will do tbh).

I am happy if we completely remove this user and start again but don’t know enough about WP or phpMyAdmin to know if there is a safe way to do this.

Cheers,
N