Why does the same font in Linux on a PC differ from the font in the e-ink reader?

Question

linux

photo reader with font "Chandas"

photo from PC with the same font

so the same line looks like here रत्नैः
Photo from PC is the right option. In it, two consonants "superimpose" on each other forming the correct tie, in the line रत्नैः the same two letters are "connected" in a different way (after a symbol similar to lightning)
and in the line from the reader the third letter "flew" down.
How can this problem be overcome?
How does the same font "work" differently on different devices?

Answer 1

Because "the same font" is rendered by different engines. This does not take into account that fonts may have the same name, but inside they are different.