UI font suddenly turn into cursive/italic

Things I have tried

Change theme, update, import theme from another vault, disable every plugin

What I’m trying to do

Hello guys, I have a problem with appearance since a couple of days, probably I messed some settings and don’t know how to fix: one of my two vaults suddenly got an interface font that is kinda italicized, not like used to do, I attach two pics, first is my vault that still is in good-old font, second is my other vault that turn into this cursive font; I tried to import the theme from the “working” vault, but is the same thing, it appears alaso with the default theme so I don’t think is a css matter; I tried as well to disable minimal theme settings and style settings plugins. Anybody knows where I can adjust this?