stop automatic switching on imac desktop 21.5-inch 2019, running macOS Ventura 13.5

I have an iMac Desktop 21.5-inch, 2019, which is up to date with macOS Ventura 13.5. Several months ago it started moving one screen out of sight when I opened other screens. Not always, and I haven't had time to correct it. It's an understatement to say it's annoying. Today it's happening when I try to simultaneously show a screen with WhatsApp and a screen with Safari. The standard answer when I search this outside of the Community is to open System Settings, then Desktop & Dock, then scroll down to Mission Control and then turn off Automatically rearrange Spaces based on most recent use. I have never had that turned on, however. That and the other three on/off buttons under Mission Control are all off. So that's not causing this. Some answers suggested for macs on other sites online suggest that it could be caused by malware, and several other possibilities. I have malwarebytes running and it doesn't show any malware. Whatever the cause of this involuntary hiding of one screen when I open others, I want it to stop permanently. The last time this subject was raised in this Community was apparently 10 years ago. The answer that was offered and accepted then was to open Terminal and write a certain command in it. I prefer to stay out of Terminal if possible. There is no slack for the slightest error in Terminal; one typographical mistake of one letter, symbol or number can cause serious and time-consuming problems there. My questions are as follows: 1. The bottom line is, how do I fix this? Is there more than one way that depends on what is causing it? Do I first have to determine the cause? Hopefully not. Is the solution to enter the command in Terminal that was advised in 2013 here still the solution now? I hope this doesn't have to be a trial-and-error process. It has already been far too time-consuming. But more fundamentally, I hope this automatically sliding of one screen I'm working on (today, a Safari screen) sliding out of sight to the right when I opened another screen (today, WhatsApp) can be permanently corrected. I hope someone has a solution. Thanks.