Internet slowing at night

For the last 3 months. I have been having severe internet problems. Anywhere from around 8 pm till 11:00. I pay for 300 down 30 up.I get 375 all day long. At times my internet speed will drop to under 1. Its been as low as .02mbps (have screenshots). I have had a technician out here.Everything is fine. I switched the modem, speed went up during the day, but still slows badly at night. I stream everything, so this is a big problem. I’ve had to resort to a mobile hotspot on my phone for my internet. .