Addon/Extension vs Userscripts - accessing <element>'s properties via Object.values()

Add-ons Development
#1

I’m in the process of converting my Userscripts into an Addon/Extension for Firefox & Chrome.

However, I’m stuck on a particular issue.

In my Userscript, I can access the 's properties via Object.values() that the website puts in.

In my Addon/Extension content_script, I cannot access the 's properties via Object.values() that the website puts in.

Sample code:

function hasCategory(theDiv, theCategory) {
    let foundTheCategory = false;
    let objValues = Object.values(theDiv);
    if (objValues.length > 1) {
        if (objValues[1].children?.props?.category === theCategory) {
            foundTheCategory = true;
            break;
        }
    }
    return foundTheCategory;
}

The above code works in the Userscript (i.e. found some Object.values()/properties to work with).

The above code does not work in the Addon/Extension content_script (i.e. did not find any Object.values()/properties to work with).

Is there a reason for this? Is there a workaround for Addon/Extension content_script to access the 's properties that the website puts in?

nb: manifest.json permissions are: “storage”, “unlimitedStorage” and “activeTab”.