If the camera is a Dome camera I would clean off the dome and see if that is the same result after the fact.. I have all types of cameras in my fleet, I prefer bullet and turret style for most camera locations but do have some dome cameras that I use in color normally and every once in a while I will turn the IR on and get reminded why they are in color lol. Anyway just a cleaning of the dome can help.. Also want to make sure if the camera has LEDS inside the dome that the gasket that is on the lens to the glass is in tact and makes full contact to the dome. Any leak will be noticed using IR..
This is a very old video that I did on Halloween one year. Normally this camera is in color at this location with lights can be seen well without any issue. The camera has been replaced with a PT that also use in color at night. Have many other cameras that are in the area and this is just kind of a fill in camera.. Audio is bad in this video so wouldn't worry about turning it up lol. Also starting the video at 112 will give better idea without having to wait lol.. Start the camera in B/W without IR and can see other IR and some other cameras in Color in that area as well with better sensors. Anyway at 112 you can see the picture no IR looks clean, then pause the video and go clean the dome off and you can see with IR on that picture looks better after the dome is cleaned off. Maybe it is just a dirty glass on your camera. Mine is not hit by rain only humid weather and camera had been there without being cleaned for a while. Video is from 2020..