Is Cards4Cash broken?

I've heard bad things about Cards4Cash, like maybe they are a scam or poorly run.* But I'm having a different issue with them. Is their website just not working?

I tried to buy a $5 gift card from them today and it kept failing. I clicked the checkout button and it would just take me back to my dashboard. The item remained in my cart, my card wasn't charged, and I didn't get any notification. I tried this on 2 different wifi networks on 2 different devices on 4 different browsers 6 different times.

I did try to pay with a Visa gift card, because I don't trust these people with my real cards. Maybe that was the issue but, if so, they didn't tell me.

*-I'm already aware of this! They seem shady AF, I just wanted to see for myself. Feel free to go into how untrustworthy they may be but I would appreciate info on my specific question if you have any.