The same just happened to me when I upgraded my FF3 from Android 9 to 10. In my case the phone wrongly shows my network provider as Virgin when my actual provider is EE (it registers on the EE network, allows phone calls, texts etc, just wrongly displays the operator name in the top bar). I got a new SIM from EE but that didn’t fix the problem. Did you (or anyone else reading this) discover how to fix this problem?
My original issue was fixed over time when Fairphone released updates. There is something akin to a data table that is manufacturers have to update to ensure that the network names are displayed correctly, and it appears they’ve introduced incorrect data again with Android 10.
I would recommend submitting a support ticket to Fairphone, and let them know your network provider as you have done here, and they can pass that on to the developers to include in a future update. Virgin is currently an MVNO (virtual operator) running on the EE network, so it’s probably picking up the wrong data - it won’t effect the running of your phone in any way though.
Thank you Chris for your fast and most helpful reply (it gave me a very useful technical insight into what was a puzzling and frustrating problem). As you suggested, I have raised a ticket with Fairphone support and will post the outcome, in the hope it will be useful to others - Vic
Fairphone responded to my support ticket to say that they were aware of the issue and that their Software Team is currently working on a fix to be distributed with the next update. It doesn’t seem to be impeding the operation of the phone so, as you were, I am quite happy to wait for the upgrade. Thanks for taking the time to help me understand the problem and advising me on the need to raise a support ticket to get it fixed. Best wishes – Vic