Our street's new security camera system has this weird flicker issue after dark

I live in a quiet area and we all chipped in for a new camera system. It works fine during the day but at night the feeds start flickering badly. We've checked the wiring and power supply, everything seems okay. It's causing missed alerts and false alarms from moving shadows. I'm thinking maybe the infrared sensors are faulty or something. Has anyone dealt with this before? Looking for tips or if we should switch to a different brand.