Variable size of portable exe in Electron and NodeJs

I am currently using Electron version 8.2.5, Electron builder ^22.8.0. I have see that the size of the electron portable app varies from 85 MB to 700 MB. At first time, it generates 85 MB, If I run the application for sometime, close the application and make minor change and build once again, it genertes 200 MB of portable exe. After sometime, my third or fourth build generates 700 MB. Although I am able to launch the application, the portable exe size is not at all consistent. I provide below the snippet to generate the portable exe from the package.json below.

"build": {
        "portable": {
            "splashImage": "..\\..\\..\\..\\1.bmp"
        },
        "appId": "com.someorg.rnd",
        "extraResources": [
            "index.html",
            "assets"
        ],
        "directories": {
            "buildResources": "./dist/*",
            "output": "installers/"
        },
        "win": {
            "target": "portable"
        }
    }

Is it an issue with electron build which internally uses NSIS ? or Am I doing something wrong with the build part? Please suggest me and help me.