This is part of our old "techniques" for such cases, but it may work
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1. While the router is on, push the reset button at the back of the router for 10 seconds
2. once you reached 10 seconds and still holding up the reset button, try to turn the router off by pulling the power cord then count for more 10 seconds
3. after the last 10 seconds, turn the router on while still holding the reset button and wait for another 10 seconds before you release it
overall, you have 30 seconds to press the reset button. Most of the cases like this, we tend to resolve it using this method, try to give it a try and see how it goes
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