Your internet connection is likely slow due to a lack of bandwidth. When more than one device is connected, the available bandwidth is split among the devices making them all slower. To improve your internet speed, here are some actions you can take:

1. Check your internet service provider’s speed:
   Check the advertised internet speed from your service provider and compare it to the speed you are actually getting. Contact your provider if you are not getting the promised speeds.
2. Limit bandwidth consumption:
   Monitor the amount of bandwidth being used on each device for browsing, streaming, and gaming and reduce as necessary.
3. Change your Wi-Fi Channel:
   Your Wi-Fi may be competing for the limited spectrum with your neighbor. Change your Wi-Fi channel to reduce interference from other networks.
4. Connect with an Ethernet cord:
   For devices that are frequently used, connecting with an Ethernet cord instead of Wi-Fi will help to increase the speed quality.
5. Check for malware and virus:
   Make sure your devices are free from any malware or virus that could be causing your performance issue.