These past few days, my computer has been inexplicably disconnecting, indicating that the network is unavailable, and then it works again after a few seconds. It's been so frustrating with this intermittent issue.
I restarted the router, scanned and rebooted the computer, and even swapped the network card, but the problem persisted, which was really annoying. Later, I thought it might be an IP conflict, so I downloaded a tool for scanning local network IPs, Advanced IP Scanner, and sure enough, I found that my computer had an IP conflict with an old phone that I rarely use. I turned off the phone, rebooted the computer, restarted the router, and the issue disappeared. What a hassle, wasting so much time.
I wanted to share this for friends who encounter similar problems. It seems that simply restarting the router does not guarantee that the IP addresses will be completely cleared and reassigned; all conflicting devices must be turned off and restarted to get a new IP.