I am on an AT&T branded phone on AT&T network. Just got the update this morning (Kansas City area).
Size = 554.33MB
August 1, 2020 Security Patch
Baseband = N986USQU1ATH3
Got August 1st updated today 564MB.
If you haven't gotten the August update, go to settings and turn off auto date/time, then change the date to a future date. I changed mine to Sept 15th. Next go to check for an update and it should then download. Just make sure to turn back on auto date/time after the update. This has worked for years to get updates on Samsung phones.