Router disconnecting and then redirects to GStatic Generate 204

Often, my router randomly disconnects to the internet. Whenever that happens, I get redirected to a site called something like "Gstatic generate 204". After I restart my router usually everything works again.

What is this? Is this normal? Could this be a sign that I am being monitored or that I have a virus/malware in my network/router or some other device?

Thank you