nested DSL Constraints don't work because compiler adds comma at beginning

The following DSL expression:
[condition]When there are

{facts} which dont match constraints=not( forall ( {facts}

( )))
[condition]When there is a

{fact} with the following constraints={fact}

( )
[condition]-

{field} has a value={field}

!= null
[condition]-

{field} has no value={field}

== null || matches "[\S]*"

with the rule:
When there are Projects which dont match constraints

• description has no value
• objectives has a value

produces:
not( forall ( ProjectRow(, description == null || matches "[S]*", objectives != null )))

everything works just as expected except the comma in front of "description".
When using the rule "When there is a

{fact}

with the following constraints" everything works fine as described in the documentation.