so what's the correct way? I always just turn off the router and ONT. If lag. Wait for few mins than turn on the main.
Weird is a bit lag now after this long break down
the correct way to do a sequential reboot is to turn both ONT and router off and let them stay off for a few minutes. in the mean time you can go toilet or do something else for a few minutes.
Now after a few minutes, only turn on the ONT first and wait until you have 4 LEDs turned on. Some LEDs are flickering is okay, depending on which ONT model you use.
For example ZTE ONTs have:
1) Stable Power LED
2) Stable PON LED
3) Blinking Internet LED
4) Stable Phone 1 LED (stable only when your phone is not in use, blinks when in use)
As long as the 4 LEDs are stable, then proceed to turn on your router. When your router in turned on, the 5th LED on ONT will lit up, which is LAN 1.
This is the so called sequential reboot. some say need to turn off router first before turning on ONT, but its all fine if you wait for a few minutes after turning both off concurrently.
If your router can't work, do a reset on your router, but never push the reset on ONT..