H&M Error RM1 - Can't Confirm My Orders

I have a strange problem with H&M. Even though all of my card and personal information is entered correctly, I keep getting the error code RM1 when I try to make a purchase. This keeps my orders from being confirmed. I've even tried to buy the same thing on a different device, but the error is still there. This is not only hard to understand, but also very inconvenient. I talked to H&M's customer service, but their suggestions didn't solve the problem. It drives me crazy to have to deal with so many technical problems when all I want to do is shop. If anyone else has had the feared RM1 error with H&M, I'd love to hear how you fixed it or what you learned from it. It's time to take care of this!