Had to take mine into the dealer, there's a firmware version where in certain cases it refuses to update over the air due to a problem with it, mine was in that situation and went over 12 months without an update and wouldn't even recognise there was an update due so had to get the dealer to do it in the end. I think it was 07/2021 that mine was stuck on and I had mine updated start of December to version 11/2022.31 by the dealer.
Ironically, the day before I took it to have the update done at the dealers, I got notification of a new update, (which was the previous update to the one the dealer actually installed) it downloaded to my phone and transferred to the car no problem but would not install. Had it on the CTek charger at work all day, that didn't do it, did a 30 mile trip on the motorway, that didn't do it and then after my commute home it wouldn't update. Fortunately I was booked in the following day anyway.
The OTA updates have been very hit and miss on iDrive7 from the start, no rhyme or reason as to which car got them and at which time.