I have a Hampton Bay remote control fan, it goes at 1/2 speed in full and medium and does not go at all in slow.
The forward/reverse arrow on the remote LCD indicates the opposite direction the fan is moving.

I have a Hampton Bay remote control fan, it goes at 1/2 speed in full and medium and does not go at all in slow.
The forward/reverse arrow on the remote LCD indicates the opposite direction the fan is moving.
Call the customer services on 877-527-0313 apparently they are extremely helpful and not that shy in sending out replacement parts etc...

It sounds like a bad capacitor, likely the entire receiver would need to be replaced, or you can take the whole thing back to Home Depot for a replacement under warranty.