Windows font viewer can't open fonts from the vault

Hi there! I’ve found an interesting bug: when unencrypted, font viewer can open my .ttf & .otf files properly. When they are moved to the vault, they can no longer be opened from there, the program says “it’s not a font file” (full russian text is in the post ending). However the files are not broken, if I copy them back from the vault I can open them again.

Cryptomator 1.6.8 (latest) + FUSE mode (WinFsp).
What can be the reason?

The full error message:

Программа просмотра шрифтов

Запрошенный файл W:\fonts\pt_sans-light.otf не является файлом шрифтов.