Excitel works fine on LAN but Frequently Disconnects on the Modem/Router (Checked 2 Modems Already)

@anant.del TL;DR: If I connect Excitel Wire to the Laptop Directly, It works fine without disconnection. But if I connect to the old TP-Link WAN Router. It disconnects frequently.

Disconnection here means ISP ---> Modem disconnects a lot. (Like link drop).

P.S.: It's not a WiFi issue as many would think, I am loosing WiFi signals on my device.

Hello, It was working fine since last update (December 24th). But today itself, I'm noticing multiple disconnections on the same modem which was working fine.

Termination Cause: SERVICE UNAVAILABLE

Termination is happening almost every 15-30 minutes.

Thread for this Issue: Excitel - Frequently Disconnecting Multiple Times Per Hour | Excitel Broadband