One OOTB BR runs when i update assigned to person in the HR case.

[Ashutosh4]

I have a weird scenario, 
Here when I create a "sn_hr_core_case_talent_management" record it has two description fields , one is normal description and the other is rich description (HTML type).
When I submit a record I fill in the details of rich description and the description is also populated normally.

But when I update the assigned to person , the description value is copied from rich description, which contains HTML tags .

During investigation I used script debugger and it mentioned that the ootb br (sys ID - 8858040c53672300ff25ddeeff7b1229) is updating the value of description , but the condition is not matching so I am not able to understand  why it is running and updating the value.

I tried to put some logs and check but in logs also it is not coming. However , the script debugger is pointing towards the ootb script.
Below screenshot is before i update assigned to person.

Post Updation of assigned to person
IT looks like this 

Which looks like the above
THis is the conddition for BR

Any help is greatly appreciated.

[New Developer_S]

@Ashutosh4 

Did you try to debug OTB BR sys_id : 8858040c53672300ff25ddeeff7b1229?
if not please paste the BR referring code here.

Accept and hit Helpful if it helps.

[Ashutosh4]

(function executeRule(current, previous /*null when async*/) {

      if(current.operation() == 'insert' && !gs.nil(current.getValue('description')))

        return;

      current.description = current.rich_description;

})(current, previous);