As shown in the attached screenshot, I have the latest Plex app (Client Version: 2026.3.0) installed. It is definitely not a legacy version.
I have also checked the settings, and no server-related features are enabled on this device. The “iPhone” server entry appearing on my Shield TV seems to be a ghost record that doesn’t exist in my actual device list.
There is no server named “iPhone” in your account to delete.
What happens after you
sign out from your plex user account on the iPhone
delete the Plex app on the iPhone
reboot the iPhone
install the Plex app again on the iPhone and sign into your Plex user account
?
Another idea: Are you actually using the server part of the Shield Plex app? You seem to have at least 2 other Plex servers, so I wonder why the Shield server is still operating.
If running the server on the Shield is indeed intentional, try accessing its settings (using the web app). Clear the checkbox in
Settings - [server name] - Network - Enable local network discovery (GDM)