Modem packet loss

So I’ve been getting a ton of packet loss that starts at the modem according to the ping plotter app. This packet loss comes randomly and it eventually fixes itself, but starts again at a later time. This is a relatively new problem as it only started two months ago and I’ve had Xfinity for years. The problem started slowly with me having to disconnect and reconnect the modem to get the internet to work again once a day, to the internet dropping multiple times an hour and being unusable. When we called for a technician to check on our internet, he checked the lines outside and said everything was fine. He also checked our connection inside and said everything was fine. Then he replaced our modem with a new one and the problem went back to its initial stages of only disconnecting once a day with high packet loss starting at the modem. It’s getting worse again and my internet is becoming unusable. Can anyone help?