Folder shows a name in ThisPC but it's not available

I have the default Downloads folder in Quick Access but also a Download (without "s") in ThisPC. The latter on click shows to be "Not available". The path is C:/ and I cannot remove or delete it in any way (even via CMD etc.) or rename.
Googled for long time without finding a good solution. Pls give an hint. OS: windows 10 Pro 22H2