TypeScript custom function not recognized in shared utility class

Question

I have a TypeScript class implements an Interface with the following declarations. In the class I imported the .js at the beginning of the class file and implemented every function. All worked fine, until I added a new function in the Interface and implemented the new function in the class. When the project is published, including deleting all files in the existing target folder, to an IIS host, the Edge browser doesn't recognize the additional function. I re-published the project several time without avail. The next day, the function is recognized. The new function is always immediately recognized at compile time. Does any know why?

form.ts: 254

Uncaught TypeError: commonUtility.isTheSame is not a
function
at HTMLInputElement. < anonymous > (form.ts: 254: 25)
at Function.each(jquery - 3.6 .0.min.js: 2: 3003)
at S.fn.init.each(jquery - 3.6 .0.min.js: 2: 1481)
at Object.submitTheForm(form.ts: 241: 18)
at HTMLButtonElement. < anonymous > (form.ts: 86: 22)
at HTMLButtonElement.dispatch(jquery - 3.6 .0.min.js: 2: 43064)
at HTMLButtonElement.v.handle(jquery - 3.6 .0.min.js: 2: 41048)

export interface ICommonUtility {
  isDate(aDate: Date): boolean;
  isEmpty($this: any): boolean;
  isTheSame($this: any, oldValue: string, currentValue: string): boolean;
  getCRUD($this: any, oldValue: string, currentValue: string): string;
  getControlValue($this: any): number;
  resetControlValue($this: any, newValue: string)
  getTextPixels(someText: string, font: any);
  breakLongSentence(thisSelectElement);
}

/// <reference path="../../node_modules/@types/jquery/jquery.d.ts" />

import { ICommonUtility } from "../appModels/ICommonUtility.js";

export class Utility implements ICommonUtility {
  isDate(aDate: Date): boolean {
   
  }

  isEmpty($this: any): boolean {
    
  }

  isTheSame($this: any, oldValue: string, currentValue: string): boolean {

  }

  getCRUD($this: any, oldValue: string, currentValue: string): string {
    
  }

  getControlValue($thisControl: any, valueSource: string = 'other'): any {
 
  }

  resetControlValue($thisControl: any, newValue: string) {

}

  getTextPixels(someText: string, font: any) {

  }

  breakLongSentence(thisSelectElement: any) {

  }
}

Answer 1

It worked when isTheSame() became public isTheSame() in the implementing Utility class. Still don't know why this is necessary.