MyCloud constantly performing a reverse lookup

As a security measure, and since I only access the drive locally, I recently restricted my MyCloud NAS from accessing the internet. This was done through my router by blocking its IP address. I now note in my router logs that the device is constantly (every 2 minutes) trying to find “172.101.86.13.in-addr.arpa”. Is this normal?

Have you disabled Remote Access/Cloud Access through the My Cloud Dashboard?

The My Cloud will attempt to access the internet among other things for NTP, check for firmware updates (if that option is enabled) and for remote access (if that option is enabled).

yes, NTP was still enabled. Thanks for the suggestion!