How do I stop "Show news and interests on the taskbar" from turning on?

Also, if you happen not to use Microsoft Edge, and you click on an item in "News and interests," it automatically opens Edge "for you"—want it or not.

Now Check your TaskManager - is it still lurking in the dark, consuming resources and doing who knows what else? all these hoops seem to do nothing but remove it from your field of view while its intended purpose keeps on running in the background.

"Next, go to Settings > Personalization > Start. Ensure the 'Use Start full screen' " no such menu point in that stupid Edge!

So, you need customers to send you evidences to isolate and fix this bug of yours that shouldn't be in the first place. It looks you are sleeping on the job, while paying customers like me have to bear this since months. I ALSO HAD TO MEND THE REGISTRY, because you failed to do your coding properly.

Microsoft should upgrade their hiring system.

The Registry Key in your post does not exist on any of my 5 systems that have this same problem. However I believe the problem is Microsoft EDGE itself. You cannot disable, remove, uninstall, nor can you terminate the process. Every time windows detects non-microsoft settings an update for Edge is downloaded that overwrites all settings back to default. Default browser, email client, network settings, removes ad blockers, or security software, VPN settings, re-enables MS Defender as default security software. However, these default settings disconnect the client from my network preventing all these ad servers and tracking apps from calling home. This process is initiated at bootup and repeated every 15 minutes rendering my MS devices basically useless and unusable. Thiese actions are deliberately targeted for individual consumers rather than enterprise controlled devices.
A four-year university in my area has implemented a decoy DHCP server setup to defeat these insecure MS defaults. Once the defaults are rewritten to a client machine the decoy server provides connection information that is bogus which prevents connectivity until the user removes the defaults, and re-enables the required network security applications. The number of Windows based clients, not owned & controlled by the school, that connect to their network have dropped by approximately 85%. In the local area the sales of non-microsoft devices has sky rocketed.

edit: taskkilling exploerer.exe and restarting it, would instantly re-enable this setting. Changing the registry key ( HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Feeds\ShellFeedsTaskbarViewMode ) to 2, seems to have solved this.