zte usb sick 120 3g modem

[Guest N3M35I5]

hey guys, dunno if anyone here can help.

iv got a ZTE 120 usb stick branded t-mobile.

i flashed it with the latest de-brand firmware and it takes any simcard( asfar as im aware)

i put my o2/giffgaff simcard into it, it asks for the pin code and then just stays on limited service and when i manually scan for networks its doesnt pick either up only orange, 3g etc but says forbidden next to them

im completley confused when i've unlocked dongles before they have all worked flawlessly