Why WebStorm shows exports in TypeScript as unused?

When I was developing a NPM library (as an ESM module), WebStorm shows that my exports are unused. How to fix it?

My tsconfig.json:

{
  "compilerOptions": {
    "declaration": true,
    "declarationDir": "./dist",
    "lib": [],
    "module": "CommonJS",
    "target": "es5",
    "sourceMap": true,
    "strict": true,
    "noImplicitAny": true
  },
  "include": [
    "src"
  ]
}

My package.json:

{
  "name": "",
  "version": "0.0.1",
  "main": "dist/index.js",
  "scripts": {
    "build": "gulp clear"
  },
  "exports": {
    ".": "./dist/index.js"
  },
  "devDependencies": {
    "@types/node": "^20.4.2",
    "fs-extra": "^11.1.1",
    "gulp": "^4.0.2",
    "gulp-sourcemaps": "^3.0.0",
    "gulp-terser": "^2.1.0",
    "gulp-typescript": "^6.0.0-alpha.1",
    "merge-stream": "^2.0.0",
    "typescript": "^5.1.6",
    "vinyl-buffer": "^1.0.1"
  }
}

gulpfile.js:

const gulp = require("gulp");
const ts = require("gulp-typescript");
const terser = require("gulp-terser");
const merge = require('merge-stream');
const tsProject = ts.createProject("tsconfig.json");

gulp.task("default", function () {
    const tsResult = tsProject
        .src()
        .pipe(tsProject());
    return merge(tsResult.dts, tsResult.js.pipe(terser()))
        .pipe(gulp.dest("dist"));
});

Behavior of WebStorm:

Why it's happening and how to fix it? WebStorm 2023.1.3 on Snap

from Why WebStorm shows exports in TypeScript as unused?