Why - It's overpriced, cheaply made cack.
There are several known faults, the biggest one being the thumb buttons frequently breaking. I think Button 2 was the most common.
I went through two of them myself, and my oppo stubbornly went through three before he finally learned from my experiences and bought something better.
Yours - Yes, I expect it is on its way out. You might be able to crack it open and fix/re-wire the switches, but it will be fiddly, as they used the thinnest and least amount of wire possible, to save costs.