Kobo Aura won't display a charcater ⇒

Hi all,

I've been reading a book (a pop-sci book) and after not being able to figure out what the author meant, I looked at the epub with Calibre Viewer and noticed that my Aura won't display this character: ⇒ (rightwards double arrow U+21D2). Author uses these as an implication.

I've tried changing fonts and even uploaded my own font but no matter what, Aura just won't display it.

I've been thinking that maybe I could force Calibre to render these out as images somehow?

Any suggestions? Thanks!