"not appreciating" is correct and is commonly used and understood in written English.
Example: She was upset that her efforts were not appreciated, so she stopped speaking up in meetings.
Of course, some people might think me the rude one for not appreciating life's little courtesies.
To my teachers for not appreciating that they were only trying to help.
Not appreciating the depth of his probable hangover, I cried and cried the whole game.
Sorry for not appreciating your spindly looks – charmingly reminiscent of a Citroën 2CV – until recently.
"There is just an inertia to not appreciating the money being made by private industry in public education".
"At some point, your skin is not appreciating the conditions," Gates said later by telephone from the pole.
The man had a lot to put up with, too, with the world not appreciating him as it should.
Men, as we know, are meant to enjoy doing things, not appreciating things of beauty for their own sake.
For instance, if you talk about Eliot's anti-Semitism you are accused of not appreciating the poetry, which is ridiculous".
Guard Down ft Diddy and Kanye West is a lament about not appreciating those around you – including Big TC.
Jessie J recently announced a permanent move to Los Angeles, spurred in part by the British "not appreciating my voice".
