Unlocked Galaxy S10+ not updating to Android 10

[djhurlburt91]

I've seen a few posts about this, but I cannot seem to "reply" to them; only post a new one.  I have a Galaxy s10+.  It's unlocked.  Shows ATT/ATT/VZW under Service Provider.  When I go to "check for update" it says it is up to date, however, I'm still on android 9 with One UI 1.1.  I called ATT and they said they manually pushed the update.  But after 48 hours, it is still not working.  I'm wondering about trying to do a manual update, but am unclear of how to find a trust-worthy source.  Or are there other things I can try?  The closest "samsung" store is over 100 miles away.

[Pugs1957]

Do you use ATT or Verizon as your carrier? What baseband version is it running?

[djhurlburt91]

ATT.  I'm not sure about the last question you asked.

[djhurlburt91]

Sorry, I see it shows G975USQU2BSGJ

[Pugs1957]

This still applies https://forum.xda-developers.com/t/at-t-sm-g975u-on-android-9-current-software-is-up-to-date.4089171...

In a nutshell ATT firmware files are not public like others so doing this manually is difficult. I can't vouch for the pay site in the link. In fact I didn't try it.