Issues with Revolut?

Klarna won't approve me for a purchase of something that is around £600. I have a good income of 70k, I have around 4k sitting in my account. I just don't want to pay for it all upfront. When connecting revolut to Klarna I am told that they can't approve me for this as they are not sure I can pay it back. Wtf ? What's funny is that Klarna did approve me for a previous item like 2 years ago when I was earning half of what I'm earning now!