Multiple Repeating Alarms / Triggers

I have two motion detectors that have been plugged into two different boards and I am getting a bunch of trips over and over and over again.  The detector is not closing the contacts as I have tested with a continuity tester.  Once it starts, it keeps going for hours and then all of a sudden it will stop.  It seems to happen if the contact is closed multiple times (valid closures) within a few seconds.  This happened a year ago and Konnected replaced the board, but now it is happening again with a different board and detector.  Since this is unreliable, I cannot use the system as intended.  I have it alerting me when I am not home and it sounds a chime when I am home.  I have had to turn all that off. 

I am an electrician so I have some knowledge of electrical circuits etc.  Has anyone else experienced this?  Any ideas?  The integration is with SmartThings.  I have attached some files. 

Any help much appreciated.