Orders are continuously cancelled due to a "possible security verification issue"

Hi, I'm at my wit's end with Best Buy Canada I'm really hoping someone can chime in.

I've been trying to order a new laptop and I keep receiving a notification that the order has been cancelled because "our system detected a possible security verification issue". My payment and billing information has all been triple-checked and confirmed. My bank (RBC, if relevant) has assured me that they're seeing nothing on their end, I have had four orders cancelled and my sister has tried to order twice using her card (also RBC) only to have it fail as well. whatever is occurring is happening on Best Buy's end. The customer service chat has not been helpful, nor has the phone line -- the only solution they propose is visiting a store in person, which is not possible since the nearest Best Buy is a >2 hour drive from my home.

Does this issue sound familiar and/or can anyone provide some insight on this? This has been very frustrating, I would go to a different retailer but only Best Buy has the specific machine I've got my eye on.

Thanks!

UPDATE: It ended up working using the Koho account I share with my partner (which I use as a debit account and didn't remember was functionally a credit card until I was reminded) If anyone is in a similar boat and stumbles across this thread in the future, maybe RBC's systems and BB's systems aren't playing nice with each other at the moment.