Can't delete strange folders/file on Web File Viewer

My Cloud OS 3 Personal & Network Attached Storage My Cloud EX2
1

Hi,

I’ve just found out that on my drive, there are some strange folders and I can’t delete them. When I connect to it in Finder (Mac OS), or Explorer (Windows), I see everything correctly

14
14882×548 54 KB

However in Web File Viewer, I see other folders, which I can’t delete.
55
55976×532 43.4 KB

Any idea of what to do and how to get rid of them?

Thanks,
Jakub