Acrobat Pro and Photoshop not working with new Monterey OS download

I'm guessing that you didn't check app compatibility before taking the plunge to upgrade from High Sierra to Monterey ... correct?

Regardless, yes, it is possible to downgrade. However, the process will require a few step. Those are:

• Have a USB stick handy. Anything on it will be erased during this process.
• Create a bootable installer of the version of macOS that you want to run. To do so, you will need access to the installer from the Apple App Store.
• Completely erase the system drive, and then, install the earlier version using the bootable installer.

Alternatively, you can skip all of this by contacting the app developers for those apps to see if they have updated versions that work with macOS Monterey.