The font hangs in the system, I can't find what to delete?

Question

Fonts

Hello !
The question is probably amateurish, but I don’t know where to dig anymore.
There is a site, only there is a problem on it. The wrong Ubuntu font is displayed when opening the page. According to the inspector, it is set first, but Helvetica, which is second on the list, should work.
I want to find the Ubuntu font and remove it.
It is not in the fonts folder, it is not in regedit in the Fonts folder, it is only in System Options -> Font Options.
How to find and remove it, who will tell you? Thanks in advance