Axis may be having different databases of it's customers - unlike an unified n consolidated one. Different functions of the bank draw data from different databases - it so appears.
When I applied for Airtel card, I used a different (official) number n email ID (official). After using it for 3 months or so, shifted it to my personal number n personal email ID.
No issues in functioning n practicality of the card. But, if I want to lodge a complaint, their website, apps... do insist on my official number n email ID. So, I can't use those channels. Luckily, Customer service works on testing it. Just in case, I need their service.