Roon remote disable

Hello,
Does anyone know how to disable Roon remote on a smartphone that is using it not properly without disabling mine?

You should be able to disable endpoints in settings/audio by hitting the “gear” icon next tot he device in questions then hit “disable”.
This is how a phone running Roon would show up on a PC:

This does not prevent them phone user from re-enabling their phone again or controlling Roon, however.
If they are not welcome on your network then you would need to block the phone from the network the Roon Core is on to keep them from controlling Roon.