@AdamsEG,

The settings to configure and see what may be causing this can be found in your router's security settings. If you are getting the alert that the attack is blocked, then the firewall settings on your router are properly working. Realistically, I believe that the only full solution is to ensure that your router's security settings are properly configured, or getting in contact with your ISP if they are from a source outside of your network.

It is possible that the alert is being caused by your network or a device on your network, so I would first try to figure out the source, whether from within your network or from the internet.

You can follow the steps in this FAQ to see where the settings are and what devices have been put on the DoS block list if the cause is inside of your network:

FAQ: How to protect the network from cyber attacks on your Wi-Fi router