Sample dial code menu with carrier mccmnc.
This is what looks like. You see 310/260 as MccMnc for carrier signal. And the adb command gives MccMnc on sim card (first 5 or 6 digits). From your picture, it looks like the the phone is on carrier MccMnc 000/00, which is reserved for test purposes only.
It is possible someone has a test network nearby (best case scenario). You may need to add 000/00 and 000/000 to your template list if this is the case.