Firstly
Do not confuse modem and router

Modem, also known as BTU or ONT, is the one that takes the fiber and converts it into an Ethernet Port for you to connect your router to

The router is the one who handles all the network connections and also gives you your WiFi

On newer setups, they give you a 2 in 1 device, that combines both into one

If your modem is faulty, call TIME and get them to replace it, free, lifetime warranty

If you want a new better router, firstly, what's your current router to compare with
But for like 200 to 300, maybe consider a TP-Link AX53?

Contact CS to change the mode of 2 in 1 into bridge mode, plug in your new router
Key in PPPOE credentials, done

Or you can try my method if you are comfortable digging a bit more
Export the backup file from 2 in 1,buy a huawei ONU (single mode, no wifi version), restore using the backup file
Remove PPPOE credentials from the settings, plug in your new router, done

Assuming you are on old
modem + router 2 device setup

remove old router
plug new router, connecting from LAN 1 of modem to WAN of router
login to time self care portal and get PPPoE username and password
enter those into new router setup
done