Script execution with Sonoff 4ch: execute only first step of the sequence

I have prepared the following script:

sonoff4ch_test_off:
alias: Test Off
sequence:
- service: switch.turn_off
data:
entity_id: switch.sonoff_100073a641_1
- service: switch.turn_off
data:
entity_id: switch.sonoff_100073a641_2
- service: switch.turn_off
data:
entity_id: switch.sonoff_100073a641_3
- service: switch.turn_off
data:
entity_id: switch.sonoff_100073a641_4

after pressing “execute” just the first channel is activated, if I press “execute” again all the other 3 channel are activated. After turning off the 4 channels, if I press again, after few seconds “execute” all the 4 ch are activated, if I wait for a while, only the first one is activated.
What is wrong in the script…

thanks in advance for the explanation.