The case entity/table in Dynamics 365 CE has a Boolean type field named Route Case.
It has a default value as Yes.
On manually creating the record from the user interface, although Route Case shows the default value as Yes
On saving the record, the value changes to No, the field is also locked.
So basically no routing rules are applied when a case record is created from the user interface.
To apply routing rules, we need to use the “Save and Route” option
Or “Apply Routing Rule” command from the Grid
This also however will not update or set the Route Case field to Yes on the case record.
Now if we create the case record programmatically, the field would be set and saved with its default values as Yes.
The same goes for cases created from Flow.
Route Case is set to Yes.
So basically routing rules will be triggered on the records created from outside the User Interface as Route Case will be set Yes for those records.
Now if we want to run the routing rules against the case record created from the user interface, we can make use of the following action –
Within Flow –
Within Plugin or any custom code–
msdyn_ApplyRoutingRuleEntityRecord can be used for other entities apart from the case.
In the case of Case entity, we can also make use ApplyRoutingRule action also.
Hope it helps..