It has been working fine for 1 year and suddenly could not connect to the wi-fi. Tried everything suggested on troubleshoot advice including factory reset and didn't work. Tried to set it up again and noticed it didn't even detect the wi-fi in the house (other devices had no problem). Does it mean the Chromcast is broken? Thanks for your advice.
It looks like alexyhui was able to solve their issue, and it's been a couple of days, so I'm locking the thread. As always, feel free to make a new thread if you have any more questions or concerns.
Have a good one!