It appears as though you cannot pass a Universal IO - String Calculation tag configured as a string to a Script tag.
Changing the Universal tag to a Numeric Calculation, but keeping the value as a string, works just fine, the Script is able to use the parameter's string value. Downside of this is that the value of the tag does not show in the tag browser.
As well, using the legacy Calculation tag, a string can be held and passed to a script.
It appears as though you cannot pass a Universal IO - String Calculation tag configured as a string to a Script tag.
Changing the Universal tag to a Numeric Calculation, but keeping the value as a string, works just fine, the Script is able to use the parameter's string value. Downside of this is that the value of the tag does not show in the tag browser.
As well, using the legacy Calculation tag, a string can be held and passed to a script.