Decision table not seeing an input variable value from preceding task


Just starting to work with Camunda 7.

I have a process with form task and business rule task.

The form has a string variable with key X1 declared as a select with list of static options. My decision table has a string input variable with FEEL expression named X1 (with the same predefined options as the form).

When I execute the process, I complete the form task providing value for variable X1.

When the task completes, I examine the decision inputs and input X1 has a Null value instead of the value entered on the form.

My understanding is that all variables defined on a form get added to the process context and their values should be available by name to subsequent tasks (including decision tables).

I hope that description of my problem makes sense. What am I missing or misunderstanding?

Many thanks in advance for help with resolving my issue!