Three network 4G

Anyone on 3 only getting 3G not 4G at the moment?

I recently swapped phones to a Sony (which is 4G LTE) and noticed it is just showing 3G (before my Samsung showed 4G).

Rang 3 and they said have three masts in Sheffield and my local one is under maintenance till Friday, and is only 3G till then.

Odd thing is I was over at Spital Hill where another mast is, and still only showed 3G.

I know from 4G.co.uk the frequencies for 4G in the UK for 3 are 800MHz (Band 20) and 1800MHz (Band 3).

I understand that some non UK 4G phones don't use 4G here as do not have 800MHz.

Live over near spital hill, amd im sat with 4G, VoLTE, no worries..

I do remember getting a txt a couple of weeks ago, saying I may experience patchy signal between x date and x date, but cant remember the dates.

Thanks, seems something of a puzzle