Quick answer: restart your router, update its firmware, check for signal interference, and optimize your WiFi settings to boost your internet speed. These simple steps can significantly improve your connection and eliminate frustrating lag. Here's the good news: more often than not, fiber internet slowdowns can be fixed quickly and easily. Luckily, these problems are usually easy to fix. Having a sluggish WiFi connection can make everything from. Many routers have a power button so you can quickly restart them. You've probably tried everything to. If the Wi-Fi speed is slow only on one of your devices, the problem could be with your device rather than the network. If it's not working to its full.