I'm using font family Monserrat to render Unicode subscript characters. These are computed values from Chrome Dev tools inspector:

Body of this element is

CH₂O₂ - example 2

and result looks like this:

Subscript characters are looking different then 2 in the end of this example.

Is there a possibility that subscript characters were taken from some other fallback font? And if YES, how to check which font family was applied to them?