on 11-05-2020 11:36
Hi have you checked to see if your SIM is properly inserted in your phone?
Also is the number still connected to your O2 account?
If all these are clear how long has it been since you haven't received codes?
If it has been long time then I will ask you to call customer service for help
on 11-05-2020 11:37
Not had any problems myself.
Try the tips here Guide: Text Message Tips (not sent or received)
OnePlus 6 (O2 & Sfr), Z3 Tablet (Three UK), iPhone 8+ (EE)