cams don't detect motion at night

[lib]

I have two outdoor cams that were working fine for the first few days. I have had them for about ten days now and they don't detect motion at night unless I have them set to 100% now. I have been reading a lot of reviews of these cams and  motion detection is the main problem issue. What could be the problem when they were working fine before and now they are not with the same settings?

[tinokremer]

Is it warmer outside then a week ago? The PIR sensors detect Infra-Red, which is basically heat. If the surroundings are almost as warm as the object you want to detect you will fail. I notice it here in The Netherlands. During the wintermonths (freezing outside), I detect neighbourhood cats in my garden. During summer it never does that.

Also keep in mind, the detection is not that far and works best when the object moves through the sensor (from side to side) and not when the object moves towards the sensor in a straight line.

P.S. I take it you checked if it's armed at night? You didn't change the modes recently?