Unfortunately this can happen occassionally and is often not due to any particular fault, error or miss-configuration.
In these cases, simply re-configuring the device regularly can prevent the issues from occurring.
In Vera this is trivial to do by clicking on the "Configure node right now" button on the device "Settings" tab.
To do this, find out the "Device #" of the device you wish to be re-configured:
Add the following LUA code to the LUUP tab in the Scene and substitute "205" appropriately:
It should look like this:
The Scene will now run automatically based on the Schedule that you have entered and the device will be re-configured.
Note: for battery powered devices, Vera will attempt to re-configure the device according to the Schedule, but this will fail as battery powered devices spend 99% of their time sleeping. Vera will then internally automatically re-schedule the re-configure operation for the next time that the device wakes up.