First, have you tried resetting your router? If you haven't I would advise you to reset it and see if this fixes the problem. Also make sure to reset your wifi adapter on your PC too if you haven't tried that yet. If you've done this, and you're still getting issues check to make sure your network adapter drivers are up to date or not corrupted. Sometimes updates can be interrupted and cause issues with different drivers. If your drivers are corrupted, you will need to have access to another computer in order to download the drivers. To check to see the network drivers installed on your Windows 11 PC, open up device manager. This will give you a list of all the drivers currently installed for any piece of hardware on your computer. From there on another device you can search Google to get the drivers from the manufacturer's website, download them onto a USB drive and connect the USB to your Windows 11 pc to install the drivers.