S21FE One UI 8 Update - No Service

[Martin08523]

Last night I got the One UI 8 update, followed by the 'No Service' issue. Showing as no SIM, SIM Manager never opens, the SIM info is all blank, the baseband version is "Unknown".

I tried, all recommended steps, reset mobile network settings, rebooting, wiping cache partition, cleaning SD card, trying a different SD..

I saw some posts about reflashing with Odin... So I thought I'd give it a go...and this is where it gets really weird.

So I'm in the UK, as far as I know this phone was a UK version (I bought it here, new from ebay - unlocked / not attached to any network), it was stock - I never messed with it.

The model number is showing as: SM-G990U1/DS, the service provider software is showing CSC as XAA. When I try to get the stock firmware to reflash, it shows as US North America Region... 

What's going on here? Is it possible this is a U.S region phone? Or has the latest One UI 8 update somehow changed the region? The Model number seems to be a U.S version too.

I am confused. Any ideas or thoughts will be appreciated.

[keith30]

It is a US device, one of the downside of buying off Ebay as you never know what you'll end up with, usually a phone with loads of problems.

[Martin08523]

It's been fine for 2 years, but yes - lesson learned.

[RevengeOneUI]

Not sure how to deal with this issue, but it doesn't have to do with it being an American phone, I have the same country code on my phone CSC XAA (I bought mine from Samsung in the us while I was there), and my phone has updated perfectly fine.
I hope you manage to figure this out.

[keith30]

It matters, because when the phone is outside of the region it was manufactured for i.e US you can have problems receiving software updates because the phone is out of region like the user has mentioned in is post. Usually buying a different sim card US (sim card) can sometimes cures that problem but not always.

[Martin08523 · Accepted solution]

As painful as it was - a factory data reset has solved this issue!

[RevengeOneUI]

Did you back up your data first?
If yes, what was so painful?

[gtshadow]

I just posted about the same problem and then found this post. I was hoping to avoid a factory reset, but will probably try it next. My phone is a US phone in the US. All other factors, including its happening after the update, are exactly the same.