How to remove MDM enrollment notification from Mac that has been owned for 2 years without issue? [duplicate]

I have a MacBook Pro (Retina, 13-inch, Mid 2014) that is running Big Sur that I recently reinstalled the OS on. This reinstallation was done after the Mac began showing an enrollment notification out of the blue. I have had this computer for two years (It was used when I got it), and after my initial wipe of the internal disk, the computer seemed fine. There were no enrollment notifications, or any indications of a past owner.

But, here we are, two years later, with a random enrollment notification. Under normal circumstances, I would have immediately backed up my data and wiped the drive, but I had installed Opencore Legacy Patcher on this computer, which made me wonder whether if would be feasible to keep my installation of Sequoia if I reinstalled.

Because of this worry, I decided that I would just delete the enrollment notification whenever it popped up, and reinstall when I had the chance. This plan was short lived though, as within a day of the notification appearing, my computer had slowed to a crawl. Because I had not installed anything else or done anything with the computer since the appearance of the notification, I could only presume that the notification had caused the abrupt change in speed.

Long story short, I wiped the disk and got the computer back to its stock OS (Big Sur), and everything seemed fine for the moment. But not an hour later, the enrollment notification was back, leading to this post. I was worried that if I left the notification untouched like I did last time, it will slow my computer down again, so I tried to remove it using various means. I have tried blocking various domains in the hosts file, and running this script, but nothing has worked.

Is there anything that you would recommend to fix this issue?

Update: I have looked at other posts on this forum, and so far nobody has been able to find a solution to this issue.