Win - NC desktop client doesn't start on OS boot, although set to start with Windows

I am going to answer my own question.

Recently, I unticked the setting for NC to start with Windows, because I was working on a script that changes a ton of files when saving and was having problems with conflicts, when saving frequently.
When I was done, I ticked the setting again and thought nothing of it. Next time I booted up my OS, the NC client wouldn’t start. I went back to the settings and sure enough, the box was ticked.
I unticked the box, rebooted the OS, ticked the box, rebooted the system, but nothing changed. I perused the Internet for a solution, but it seems my google-fu (actually ddg-fu) is not what it used to be; I turned up empty.

Starting the client manually with the crank handle works and the client does what the client does and has a poker face about the issue of not respecting the ‘start client with windows’ setting.

Funnily enough unticking the box in the Nextcloud settings also deactivated the Windows setting that is supposed to have NC start with the OS. Change that setting and hopefully, you’ll be all set.