All the glitches in my old iMac migrated to the new Mac Studio

There are people here who suggest that it's best to use Migration Assistant only to transfer your preferences and settings. They recommend that the customer apps be newly downloaded and installed with fresh versions. Last, files are culled and manually transferred. I support this process when an older computer clearly has problems because why transfer them as well?

You may want to consider doing the following. First, back up your files to an external disk. Then reformat the disk and reinstall the operating system to get a clean unaffected OS. Then newly install your other apps. This will give you a Mac without the old prior problems.

There is nothing wrong with using Migration Assistant. How it is used is really the key. It is important to first carefully read and understand the instructions. Then we have the options to (1) transfer our preferences and settings, which most of us would do, (2) transfer all or none of the apps or none. Most people do without any issues. (3) Transfer all files or none. Usually this should not be a problem. What we do really depends on whether there are any issues with the old computer and whether the old computer's apps will work in the new one. Certainly, not from a PC to a Mac. Glad you got things working as you wanted.