High data usage in iOS17 for Software Updates when App Store cellular data was turned off?

I updated to iOS 17 2 days ago while on wifi. I turned off cellular for MANY apps over the last 2 months as I only have a 12GB data plan, and rely on a fair bit of that data for work.

Software Updates in the last 12 days has used 3.63GB. Yes. GB. With cellular data turned OFF for the App Store. To say I’m furious right now is an understatement. What the heck is going on?

My settings are:

App store - cellular OFF

App store - Cellular Data > Automatic Downloads > OFF

Automatic updates - ON, wifi only

Data Mode - Standard (just changed this to Low Data Mode)

It’s showing there’s an iOS 17.0.2 available but it’s not downloaded yet since I’m not on WiFi, like it’s supposed to. So what in the world is happening?!

Please help - I’m relatively tech savvy and I’m lost here, not to mention furious as I’ve been so so careful about data this period and suddenly my usage has doubled. I still have 18 days left in this period and this thing used 1/3 of my month’s data in 2 days!