Hi Bowden
It's a strange one but please could you try this
Turn power off router on the switch at back of router
Unplug the power lead from the router in full (so no power lead is connected to router at all)
Wait 5 minutes (usually a couple of minutes would work but 5 to be sure)
Turn your computer off
After 5 minutes have elapsed, power up your router
After a minutes or 2, power up your computer once your router lights are steady, showing router is working
Try to connect
If you still cannot connect, set your computer nic to dhcp (if it is not already)
Try again
If that does not work, then I believe your only real option is to factory reset your router and start again
I apologise if I'm wrong though, as we do not use your router
Many thanks
John