I gave up on trying to run Parallels and bought a Mini-PC off Amazon for like $350 (or could use an Intel Mac mini running Bootcamp). I have it running without a monitor on my network and use Microsoft Remote Desktop to access it. I find this WAAAAY better than using Parallels. The performance of the machine is much better, it doesn't slow down or take resources away from my Mac, the performance of Remote Desktop is virtually identical to being right in front of the computer, and best of all I can access my PC from any computer over the Internet too. So when I'm working on my M1 MacBook in a cafe I can remote connect to my mini-PC at home instead of having to use a external drive on my MacBook to store the massive Parallels disk image and then having to keep all my files in sync. I also can keep the Mini-PC completely out of sight, like in a cabinet, and never have to pay for yearly Parallels updates again. I highly recommend you ditch Parallels and try this solution.