Curious question. Is the machine a secondhand machine or is it brand new as in you are the first owner? If it is a secondhand machine, did it possibly ever have a western digital hard drive?
another question is, did you find the start up folder using the method I provided or did you simply navigate manually to that folder? If you navigated to the start up folder manually, you may not have found the one that my method that I provided takes you to because it is a different one.
I was looking at the picture where you show the start up folder and the very first thing I see in the path to that store the folder you are showing says YouTube if you go up one level above that YouTube folder is there an actual YouTube folder that you can see? If yes, can you rate click on that particular folder and take a screenshot of the properties ? If my hunch is correct, there’s just some thing not right about that folder and you should be able to simply Move all of the items in the YouTube folder out of the YouTube folder, leaving the YouTube folder, empty, and everything moved into the folder that the YouTube folder sits in and then go ahead and delete the YouTube folder. Before you do all of that can you take a screenshot of the folder that the YouTube folder sits in as well as the requested properties for the YouTube folder?
I have personally seen crazy things like this happen on my own machine. Some sort of a ghost folder gets created and wacky. Things happen. I once experienced a weird sort of glitch that was driving me nuts where every time I would sign out of my iCloud control panel on my windows computer and sign back in. It would start creating ghost desktop folders and any time I would look at an explorer window, I would have to scroll through and close so many of these ghost desktop folders to clean up what I was looking at. It was beyond stupid. I worked with both Microsoft and Apple to try to figure it out. I even resorted to trying to tweak it out of the registry , and even that didn’t help very well. I wound up having to uninstall the iCloud control panel and reinstall it and not use the photos synchronization portion which I don’t use anyway. For some strange reason that was the crazy culprit. My life exists in the land of crazy .