I went into my hero gallery to look at Genji's stuff but when I selected him my coins fell to 2800 from 3800. Does anyone know why this happened? I don't know if this helps but I play on Xbox One.
This is a fairly common glitch in 2 ways.
If you commonly switch between devices a bit, or you have played on the PTR, when switching back to another device, you may lose coins or XP or other currencies. I don’t know why this happens. To be honest it is Blizzards fault.
This can happen if you have tonnes of coins and you have used about 1 thousand of it, the currencies can glitch out and you may end up paying less, or more than what you bought it for.
I know this answer is late, but I hope it helps.