Motion detected but no recording

[user_813021730377858_813021730377858]

I’m having a problem that I can’t seem to find a solution to and I’m hoping for some help.
I have a RLN8-410-E (firmware H3MB16). I have four of the 5MP PoE cameras connected.
All have been configured to record when detecting motion and have been working perfectly until recently. Recently, one camera is still detecting motion, but only recording it sometimes. The problematic camera is also triggered to record when another camera detects motion. All three of the other cameras still record with motion detection, even the other camera that is supposed to trigger the problem camera. There doesn’t seem to be any rhyme or reason for when it does actually record.
I've tried several things including moving the problem camera to a different channel and the problem stays with the camera. Any suggestions?