Roller shutter - domotics sometimes miss one

[Haeuslebauer30]

Hi all,

I have 12 roller shutters in my house. I open and close them over a blockly schedule in domotics. The roller shutters are z-wave from fibaro.
In general everything works perfectly. But sometimes it seems that the signal to some roller shutter doesn't arrive and some shutters doesn't close or open. Then I have to push the switch for closing/opening the shutters again.
I thought that the z-wave protocol ensures that a signal really arrives and when it doesn't work that it send the signal again from itself. Isn't that right?

Thanks in advance for any help