Plexx App - Onn Streaming Box

I recently picked up an Onn Streaming Box to replace my existing Roku device. Everything works great except I have noticed an issue when pressing "Left" to rewind 5 or 10 seconds. Sometimes (not every time oddly) it doesn't rewind, instead it skips ahead by a minute or two, which means I then have to go to the time bar and rewind that way.

Anyone else have this problem or know how to fix it?