IonCard renders in two layers when, in combination, it has background-image and routerLink attritubte

I am using the IonCard with a background-image set in the CSS. This is fine until I add routerLink to the card to navigate to another route - they’d appear another layer of the card on top as shown
Screenshot (612)

this doesn’t happen (or perhaps is not noticeable) when the card has no background-image.
It doesn’t happen also when I did not use the routerLink