Every time I receive an NPC shop discount of 15% off, there's a 502 error. I generally don't get the 502 errors otherwise, but that event is a constant 502 error and has been for weeks. The only reason I know I have the Main Shop Discount buff is because it eventually (3-5 minutes later) appears in the "Subeta" section I have on my dashboard.

Same for me, for about a week now. The item is bought and discount granted okay but the purchase confirmation page just never loads.

In the past few days, perhaps a week, I've been getting the same 502 errors as the OP, but just a moment ago I got a 504 error instead and, surprisingly, I got the discount buff but NOT the item I was trying to buy.

Same for me as well, other purchases are usually fine. Just when I get the discount I have problems.

This is still a problem, two weeks later.

Didn't have a problem at all yesterday! And I love the sidebar alert that was added! That is so helpful! - Can we get a similar sidebar alert when there's a Wizard bonus quest buff?