Airtel Fiber router is updating No-IP with the wrong IP address

I'm trying to use No-IP so I can access my home network from outside.

The No-IP update on my Airtel router says Accepted, but it's updating the wrong IP.

My router WAN page shows my IP as 97.33.xxx.xxx, and No-IP also updates to that address.

But when I check my public IP from my PC using ipify, ifconfig.me, or OpenDNS, they all show 122.161.xxx.xxx instead.

Because of that, my No-IP hostname points to 97.x.x.x instead of 122.x.x.x, so I can't reach my router or my Minecraft server from outside my network.

I'm using the Airtel AOT5222ZY router with PPPoE.

Has anyone else seen this? Is this an Airtel thing, a router bug, or am I missing something?

Any help would be appreciated.