Sorry for the double reply. Just had a thought and wanted to make sure you saw it. If you have set your modem to bridge mode, make sure your personal router has a good password, and isn’t just using the default credentials. Since the modem is passing all the traffic straight to your personal router, your router is basically acting as your network firewall… Which means it is handling all of the security; Keep the firmware updated, (depending on the brand, it probably has an auto-update option!) and change the default login credentials.

Also, since you know how to port forward things, consider turning UPnP off. It’s a security risk, (it allows virtually any device on your network to request open ports, which means malware and insecure IoT devices can request open ports too,) but many routers ship with it enabled by default because they don’t want to deal with people calling in to complain about their washing machine being unable to connect to the internet.

I figure you probably already did… But I’d be negligent if I didn’t at least mention it.