Plusnet Mobile carrier?

[#1]

I own an old Oppo Find 7 phone. Quite high spec for what it is.

I charged it up and inserted my Plusnet sim tonight and the carrier is showing as T-Mobile which was a bit of a shock. When I set it to EE it lost the signal and reset itself back to T-Mobile. The APN shows as EE Anywhere so I'm slightly confused now. Some of the APN settings such as the Proxy and a few others weren't set so I entered them from the example shown on here but the carrier still shows as T-Mobile.

My other phone that I normally use is a WileyFox Swift and the network is correctly shown as Plusnet on that.

Any ideas?

Thanks.

[#2]

Mine currently shows as EE, sometimes it shows as EE-Plusnet and sometimes as just Plusnet. Nothing to worry about if it works and certainly nothing to be 'shocked' about.