RecordSaving event getting cancelled but still fields are being saved in the object - ISSUE

Summary

RecordSaving event not getting cancelled properly.

Content

Hi All,

I am trying to make a REST API call to check for a field value is present in the system or not. I am using fetch/promise. And once that promise is resolved on the basis of the result i am cancelling the event. { I also tried first cancelling the event and then making the fetch/promise thing but did not work for me}

Can anyone let me know what could be wrong with this code?

Version

Oracle Service Cloud 20D (Build 268), Browser UI Version : 3.21.02.12-b0003

Code Snippet

extensionProvider.registerWorkspaceExtension(function(workspaceRecord)
{
workspaceRecord.addRecordSavingListener(function(event){

workspaceRecord.getFieldValues(['Org.Parent','Org.OrgId','Org.C$OrgCode','Org.C$CreatedByAc','Org.C$CreatedByAbc']).then(function(IFieldDetails)
{
						
	var p_org_id = IFieldDetails.getField('Org.Parent').getLabel();
	var org_id = IFieldDetails.getField('Org.OrgId').getLabel();
	var org_code = IFieldDetails.getField('Org.C$OrgCode').getLabel();
	var created_by_ac = IFieldDetails.getField('Org.C$CreatedByAc').getLabel();
	var created_by_abc = IFieldDetails.getField('Org.C$CreatedByAbc').getLabel();
        console.log("p_Org Id(s): ",p_org_id);
	console.log("Org Id: ",org_id);
	console.log("Created by AC : "+created_by_ac+" | Created by ABC : "+created_by_abc);
	if(created_by_ac == "Yes" && created_by_abc == "[No Value]"){							 
           Promise.resolve(checkCodeExists(org_code,"ac",org_id)).then(function(value){
	          var codeExists = value;
		  if(codeExists == "code already exists"){
				console.log(event);
				event.getCurrentEvent().cancel();
			        // alert("Code already Exists in the System");
		  }
		  console.log("Cancelling event: "+event.eventHandler.cancelled);
	   });
	}
	if(created_by_abc ==