ISY-994 Turns lights on but NOT off

Anyone have a clue why this is happening? I have some floodlights connected to an insteon switch that turns on and off perfectly from the ISY Admin, Portal, and Mobilinc. I also have a program that turns the lights on 30 min prior to sunset and another program that is supposed to turn them off at 8:30pm.
 
The lights turn on almost every night (although sometimes it doesn’t work) but the Turn off program NEVER works. The Turn off program is enabled and is virtually the same as the Turn on program.
Any ideas?
 
Here are the programs:
Turn On Program
If
        Time is Sunset – 30 minutes
Then
         Set ‘Floods’ On
 
Turn Off Program
If
                Time is Sunset + 3 hours
Then
                Set ‘Floods’ Off

This is what I do to turn lights off after a specific time.
 
 
Turn On Program
If
        Time is Sunset – 30 minutes
Then
         Set ‘Floods’ On
         Run program 'Lights Off'- (Then path)
 
 
"Lights Off" (This program should remain disabled)
If          (No conditions)
     
Then       Wait 3 hours
                Set ‘Floods’ Off


 

If the lights turn On most times and not Off.
Another thing could be poor communications to the lights.
On signal is marginally getting there. Load is making some noise or signal sucking. So the off never gets there properly.

These can also be combined. (once comms working)
 
Program
If
        from Sunset – 30 minutes
        to Sunset + 3 hours
Then
         Set ‘Floods’ On
         Wait X hour
         run (else) Program
 
Else
         Set ‘Floods’ Off

Thank you for the comments! I combined the programs but I think noise might be my issue. Any good way to determine noise on my lines?

If the computing equipment is on the same circuit as the PLM. Many are known to absorb Insteon Power Line commands or make line noise.
You could temporarily use an extension cord for the PLM to a different circuit. Then see if things changes.
You could also find the circuit that the lights are powered from and turn off the circuit. Then see what other devices go off and disconnect them. To see if anything changes.

Swap the lights for an old incandescent bulb  to try it and prove where the noise comes from.