Can't import a complete url into an url field with feed-me Description

I have a JSON feed which contains an external URL like "https://example.com" (entries/external_link/url).
There is no error in feed-me logs when I run it, all the text data and assets are imported without any problems. Except for my URL field. I get "[ ]" instead of "https://example.com".

Any help on this ?

JSON exemple

{
    "entries": [
        {
            "id": "140",
            "type": "regular",
            "title": "Banner import title (fr)",
            "subtitle": "Banner import subtitle (fr)",
            "body": "&lt;p&gt;Banner import body&amp;nbsp;(fr)&lt;/p&gt;",
            "internal_link": [{
                "type": "node",
                "title": "test",
                "id": "6",
                "cta": "Banner import link text (fr)"
            }],
            "external_link": {
                "cta": "Banner import link text (fr)",
                "url": "https://example.com"
            },
            "images": [{
                "url": "",
                "caption": ""
            }],
            "placements": [],
            "postdate": "2019/12/10",
            "status": "1"
        },
    ],
    "nextPage": "",
    "length": 20,
    "totallength": 23
}


Additional info


Plugin version: 4.1.2
Craft version: 3.3.17
Have you tried to make external_link an array?

"external_link": [{
    "cta": "Banner import link text (fr)",
    "url": "https://example.com"
}],