Trying to downgrade from Ventura to Monterey, Freezing when installing from USB drive

Thanks for the additional information.

macOS 11.x Big Sur is the OS which originally shipped on a 2020 M1 Mac from the factory so you should be able to install either macOS 11.x Big Sur, or macOS 12.x Monterey.

Have you used the SanDisk Extreme Portable SSD with this M1 Mac before? The reason I'm asking is that not all third party devices are compatible with an M1 Apple Silicon Mac (especially some older devices). Also, is the SanDisk Cruzer thumb drive a USB3 version? If not, then the thumb drive is likely to old & slow to be used as a boot drive even for the macOS installer. Generally the SanDisk thumb drives are fairly good as far as thumb drives go.

Make sure you disconnect all other external devices except for the macOS installer drive.

Use the instructions in this Apple article for creating the bootable macOS USB installer:

Create a bootable installer for macOS - Apple Support

Do either of these SanDisk devices have a USB-C connector or are they using the older USB-A connector? If you are using an adapter, then maybe that adapter is the source of the problem. What adapter/dock/hub are you using? If the SSD (or even the thumb drive) has a USB-C port, then make sure you are using a Thunderbolt USB-C cable to connect the SSD since not all USB-C cables support Thunderbolt and USB3. Usually these cables will have a lightning bolt icon on their USB-C connector.

Before doing erasing your Mac, make sure to have a good backup of your data.

Also, when erasing the internal SSD once you get a working macOS USB installer, you must be very careful to only delete the "Macintosh HD" volume which should prompt you to delete the "Volume Group" which you want to do. Do not attempt to delete or erase anything else on an Apple Silicon Mac, since there are some other hidden Containers on the internal SSD which are necessary for even booting into the special boot options menu on the M1 Macs.

Use Disk Utility to erase a Mac with Apple silicon - Apple Support

What is the exact model of your laptop? This is very important information especially to make sure it is compatible with macOS 12.x Monterey. You can get this information by entering the system serial number here:

Check Your Service and Support Coverage - Apple Support

Jeffc113 wrote:

I have followed all the steps to making a bootable USB drive for Monterey. I erase the drive, startup in recovery and click to install Monterey.

Which are you using to boot the installer? The USB stick or Internet Recovery Mode?

The next screen is a language selection. Once I press the arrow in the bottom right hand corner of the box, the computer freezes. The mouse pointer has delayed movement and occasionally the pinwheel pops up. I have left it for over an hour and nothing happens.

How was the Mac working before attempting to reinstall macOS? Why are you downgrading from Ventura? The same reason may be why you are having issues reinstalling macOS.

It is possible the USB stick or your Internet connection is not good enough for this procedure. Try using a different USB stick (especially a different brand) since Macs are very picky about the drives used for booting and the quality of USB sticks is extremely poor. Also, make sure to connect the USB stick directly to the Mac since adapters, docks, hubs may cause problems. Also try using a different USB port (if a laptop, then especially on the other side).

I have been on the phone with apple support and was told once the computer has been updated to Ventura, it's not possible to downgrade.

If the Mac shipped with macOS 13.x Ventura from the factory, then it is indeed impossible to downgrade the OS on it (there are a few rare exceptions). If the Mac shipped with an older OS on it from the factory, then you can install any OS from that point to the highest supported version of macOS allowed by Apple for that hardware. Again, this is why it is so important to post the exact model of a Mac when asking for assistance on the forums.