The normal script supports returning a list of elements such as

return ["Option 1", "Option 2"] 

but when a pipeline is run by a timer or automatically in case of a multi branch pipeline then the script part does not get evaluated and falls back to the fallbackScript.

Unfortunately returning a list of elements does not work in fallbackScript. Even though the examples showing a list being returned, only the first element in the list is taken. We have to join the elements to one string but this causes other issues down the line.

return ["Option 1,Option 2"]