Man in the middle attack & connection problems

I am having several issues and not sure if related.    The most concerning is, Tuesday morning 9/12/23 at 5:55 AM, I turned on my pc and got a alert from Norton AntiVirus of a Man in the Middle Attack on my Network,  I clicked on details and it said ARP spoofing detected.  Also, in my system tray when I hovered over the internet icon it had a 2 after my network name. I turned on Nortons Secure VPN and changed both my network name and password. 

 Today, I was looking at my Xfinity app on my phone under the WiFi equipment list and we have one called RingDoorbell-81, we don't have a ring doorbell or any of their other devices, I cant delete it because it says first disconnect from your home network and I don't actually have it, so I paused it.  On device type it says misc device.

Also, we have been having connection issues with the internet.   For the past couple months the modem has been randomly restarting itself and since this past Monday, 9/11/23, both of our wireless boxes, one is an Xi5 and one is an Xi6, have been restarting themselves and freezing or not responding to remote commands causing us to have to unplug and reboot them.  Also they won't turn off unless we unplug them.    

Anyway, I don't know if this is all related or not.   The connection issues have been going for several months before this Man in the middle Attack, so I may need a technician to check on the connection issues, I only have the 400 mbps internet and that could also be the problem since we have 2 wireless boxes plus I'm working from home all day.  Is there anything else I need to do regarding this attack and ring device showing up that I don't own? would getting a whole new modem help?