Forma Kobo changes system font after connecting to pc

[miza001]

I did a factory reset on my kobo forma, but now I've run into a weird issue. The default system (UI) font changes itself to a strange bold font everytime I connect my ereader to my pc. Then it randomly swaps back to the default font after I start using it, but some elements remain in the weird font.
I don't really know what is going on, I did put two custom fonts on my ereader, but now deleted them to see if that caused the weird issue but it's still happening. Any ideas?