Perhaps we need o2 to make a sticky on this subject in all the relevant forums like the broadband sections do.
Saying that they know the issue and are working on it and this is the temporary work around.
I am not affected by this as I do not even have 3g within 7 miles of me in all directions lol.
But why have 3g switched on if all you are using it for is calls/txt on as o2 gsm network is normally fine and on most phones it is a few key presses to turn on/off and it will save battery life, and also if on wi-fi in office or home why have 3g on as well as your data will be through wi-fi.
When I do find 3g near me as it is rural it works as it should, as it is not over subscribed.
iPhone 11 Pro 256gb on unlimited data
iPad Pro 12.9” 2020 256gb refresh o2 family discount
Apple Watch series 4
My first mobile was in 1995 a CM-R111 from sony on Cellnet.
Wincanton South Somerset (Full 4g 3G 2g indoor coverage) Remember we are all customers here not customer services