Receiving debt collection calls after moving to India

Moved to India a couple of months ago and as far as I know I don't have any pending payments out there. Paid all my bills, premiums, credit cards before moving out of the US. I switched my US number to Tello to be able to retain the number.

I've been getting calls possibly scam calls from US numbers which I don't pick up, but they leave a cliffhanger automated voice message regarding "pending debt activity, please call this number". No human speaks so I'm pretty sure it's scam.

I'm wondering if anyone else also started seeing such calls after moving back to India. I ensured I have no pending credit to repay on my Experian credit report as well. What can I do in this case? I can report spam and move on, but I'm worried about the slightest possibility that this could be a real debt?