Frequent disconnect at night

For the past 2 weeks I have experienced frequent disconnects at night and into early morning. Connection seems stable during the day with great download speeds. Around 9pm will loose internet frequently  for several minutes.  Even when use is minimal in the middle of the night I can see our security system logs switch to cellular backup periodically throughout the night. I replaced the xFi modem today because it was a couple years old and did not support the download speeds on our plan. Replaced with Netgear 2050v.  The same issue continues to happen however. I was not able to resolve with Xfinity support via chat. I wonder if the issue is the signal coming into the house.  TV tends to work fine but I have noticed some on-demand content is very pixilated at times. Tried to get technician to come out but Xfinity canceled the appointment since internet was working well in the middle of the day. Feeling a bit stuck. Appreciate any advice.