ZWave switches failing to come on - Zigbee OK - same single command sent to both types

Is there an issue where ZWave switches would be better being commanded twice to switch on in the same routine?

I have two ST outlets connected to floor lamps and a dual relay Fibaro (not officially supported) switch to turn on/off my boiler or enable/disable the timer for the boiler.
The scenario is I arrive home and my iphone triggers both lights on and the boiler to turn on in smart lighting. I am finding that the lamps are on but the boiler has not switched on. I can switch the boiler on fine by manually selecting the switch on the ST app. I also have a very simple routine boiler ON. If I select this in the app, sometimes I have to tap it twice before the anything happens.
As using ST to switch on the boiler seems so unreliable, especially using time schedules, I have reverted back to using the boiler timer and ST to only enable/disable the timer or turn it on add hoc.
I will have to say that since owning this product, its reliability is questionable when using it in any serious capacity.