I would HIGHLY recommend that before gaining more experience with webcore and/or ST home devices, don’t use any security/lock related pistons, automations.
Even with pro coders (there are many in this forum) things can still go wrong because ST systems are not fully reliable YET.
The command is 'speak text and resume," you are correct but sonos is not really caring about that one:))) in my house it sometimes work and sometimes doesn’t.
What I do is,
With (Never Cancel Task)
sonos
Set level to 80
Speak text "bla bla"
Wait 5 seconds
Set level to 35
Play - what ever I want.
It won’t be the same song biut atleast music will be back.