Macbook Pro "updated" from Big Sur to Catalina?

[VoluntaryViking]

I'm not a Mac person but I recently started using the one my gf used to use for work and I've been getting it up to date as it asks to be. It just went from big sur to Catalina. I noticed something that worked before didn't work. I checked the releases to see what would be next. I found Big sur is newest so I'm not sure why the updater wanted to go backwards.

Any suggestions how to fix it? I tried to no avail.

 

[Cory Cooper]

Hello and welcome.

I haven't heard of this, as the only way to downgrade from Big Sur to a previous version is to perform an erase and install.

Maybe the Mac has separate disk partitions with Catalina and Big Sur installed?

C

 

[TonyAguila]

It’s probably the firmware of the Mac. Since it came from a work environment, someone at IT might have disabled the automatic firmware update when updating macOS. Try restarting in Recovery (cmd-R) and see what macOS version it offers to reinstall. If it’s Big Sur, then you are in luck. Go ahead and proceed.

If it still tries to reinstall Catalina, quit Recovery, restart and go to App Store… from the  menu and search for “macos big sur.” If it shows up, click on View and in the next window, click on Get. Your Mac should start downloading the Big Sur installer into your Applications folder. When done, it will ask you to reboot in order to finish the installation. Good luck!

 

[Bayer]

Check your iMac version, and which firmware it can update to. Is it an old iMac? The older ones only upgrade to Catalina (I cannot upgrade from Catalina to Big Sur on my old 2013 iMac, it is not recommended).

 

[TonyAguila]

This can help clear up a number of unknowns about your iMac. In Finder, go to  -> About This Mac, and when the “about” window opens, double click the version number of your macOS to reveal the build number. In my case, it’s “Version 12.0.1 (21A559).”

Then click on the “System Report…” button. Copy the model identifier. The format should be iMac#,#.

Copy the system firmware version (a series of numbers and periods). Don’t bother with the iBridge information. Please post the information here to help us pin down, hopefully, the probable source of the problem.