I have an activity with one parameter (an id) that I am calling from a flow.  I am able to call the activity successfully from the flow & an option to set the activity's parameter exists, however, Pega is only allowing a hard coded value for the parameter.

When I do hard code a value, the flow calls the activity and works as expected.  But obviously I don't want a hard coded ID to be passed as a parameter, and instead need to dynamically set it using a property.

See screenshot below, where the parameter is showing and allowing me to set it.  However, it is not allowing me to choose a dynamic value / property & instead requiring I type a hard-coded string.

Note that I have the same issue loading a Data Page from a flow (I can set parameters, but must hard code the string value).  When calling the same Activities or Data Pages from other rules in Pega (Sections, Activities, etc.), I can dynamically set these same parameters.