Hindi Language Fonts not being displayed by Firefox
As you can see in the image attached below, Firefox is displaying weird characters instead of Hindi font. Also I the "Show encoding text options" is set on "Unicode" already. I am using version 78.3.0esr (64 Bit) for Linux.
Wšykne wótegrona (1)
You may see little boxes with the hex code of the character if you do not have a font installed that covers this Unicode range, so make sure to check your software management. For me FreeSans is used for Devanagari (0900-097f).
See Devanagari: