I'm having a problem selling or buying things in any number more then 1.

I'm only able to sell/buy 1 item at a time. I can not adjust how many at all. I press a to sell, the window for quantity pops up. No matter what button I press, only 1 is sold. I even tried with a keyboard. I can not adjust how many I want to buy/sell. I had switched the y and a button when I started, I thought that was the problem but I reverted it back and no change. This is really annoying. For example, I grinded the frogans, had 174 webbed feet to sell.  All I can do is press a like 348 times to sell them all.......  I can't even but silver in my market wallet.   Well I can.....1 silver at a time.

Help!!!!   This is on Xbox