Ubuntu Studio looks different after release upgrade from 20.04 to 22.04. How to change it back?

I just upgraded Ubuntu Studio from 20.04 to 22.04. I don't like the new appearance. How can I make it look like it did in version 20.04?

Did you read the release notes for Ubuntu Studio 22.04 LTS ?

https://ubuntustudio.org/2022/04/ubuntu-studio-22-04-lts-released/

In it you'll note a rather significant warning

"Due to the change in desktop environment that started after the release of 20.04 LTS, direct upgrades from 20.04 LTS are not supported and may only be attempted at-your-own-risk."

So you'll need to ensure you haven't suffered system breakage, as what you've done is not supported because of the breakage. You can still use a Xubuntu based system with Ubuntu Studio (ie. Xfce like with 20.04, but in 22.04), but you need to install Xubuntu 22.04 LTS and then run the Ubuntu Studio installer script.

The release-upgrade offer you accepted is the same for all Ubuntu systems, as is offered as part of the Ubuntu base code, however even the JammyUpgrades documentation that applied to that upgrade (which should be read before accepting upgrade) also warned not to upgrade for Ubuntu Studio systems.

FYI: You maybe able to salvage your issue, but problems may exist & require time to fix. They may also not all be evident yet, but appear when you try and use your system in normal usage (as was detected in QA).

To change it back, you can just add Xfce (xubuntu-desktop) to your system, but that may not help the breakage that may exist in your system, and may just make it worse.

Well, software changes. But if you preferred the old look, that was the Xfce desktop, and you can get it back (albeit a newer version of it), by running:

sudo apt install xubuntu-desktop

Ubuntu Studio has changed to another desktop, KDE.

There's no need to reinstall everything*. When you run the above command, it will ask you to change the default display manager. Then, when logging in, you will have the option to choose between KDE and Xfce. Later, you can uninstall KDE if you wish... that's a whole different topic though.

(I have personally switched from Ubuntu GNOME to Kubuntu before by "just" installing kubuntu-desktop, that is why I have some confidence that this method works.)

Ubuntustudio changed it's desktop environment. While 20.04 is the last version which uses the xfce desktop, all newer versions use the KDE plasma desktop.

Due to this major change in the OS, upgrades form 20.04 to newer versions were never supported, please take a look at the release notes, you should have better done a fresh install.

Since you report a lot of problems I'd recommend to do a fresh install. If you want to stick with the xfce desktop, I'd suggest to install Xubuntu and then in Xubuntu you can install the package ubuntustudio-installer, so you'll get the desktop environment you are used to with all the functionality of Ubuntustudio. Please see this page.