POST events via API error

Hi!

I got an issue trying to create events via API. I always get this error:

{"code":"empty_content","message":"Le contenu, le titre et l\u2019extrait sont vides.","data":{"status":400}}

I do set correct Content-Type, so it’s NOT about https://stackoverflow.com/questions/46021570/wordpress-rest-api-acting-like-no-data-is-sent

This is how I post:

	$data_string = json_encode($events_json);
	
	$curl_post_header     = array(
		"Referer: https://xxx.ch",
		"Origin: https://xxx.ch",
		"Content-Type: application/json",
		"Cache-Control: no-cache",
		"Pragma: no-cache",
		"Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8",
		"User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_3) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/13.0.5 Safari/605.1.15"
		,"Authorization: Basic ".base64_encode($GLOBALS['wpUser'].":".$GLOBALS['wpPass']).""
		,'Content-Length: ' . strlen($data_string) 
	);		

	printr($curl_post_header,'POST HEADER');
		
	$curl = curl_init();
	curl_setopt($curl, CURLOPT_HTTPHEADER, $curl_post_header); 
	curl_setopt($curl, CURLOPT_URL,$GLOBALS['update_url']);
	curl_setopt($curl, CURLOPT_POST, 1);
	curl_setopt($curl, CURLOPT_POSTFIELDS,$data_string);
	curl_setopt($curl, CURLOPT_COOKIEFILE, $GLOBALS['cookie_jar']);
	curl_setopt($curl, CURLOPT_COOKIEJAR, $GLOBALS['cookie_jar']);
	curl_setopt($curl, CURLOPT_RETURNTRANSFER, true);
	curl_setopt($curl, CURLOPT_CUSTOMREQUEST, "POST");
	
	curl_setopt($curl, CURLOPT_HTTPAUTH , 'CURLAUTH_BASIC');
	curl_setopt($curl, CURLOPT_USERPWD, $GLOBALS['wpUser'] . ":" . $GLOBALS['wpPass']);
	
	curl_setopt($cn, CURLOPT_VERBOSE,true);  
	
	$err = @fopen('gigi.txt', 'w');
	curl_setopt($curl, CURLOPT_STDERR, $err);	
	$server_output = curl_exec($curl);
	rewind($err);
	$xerr = @fread($err, 16 * 4096);
	fclose($err);
	printr($xerr,'curl errors');
	
	printr($header,'header','green');
	
		
	$headerSize = curl_getinfo( $curl , CURLINFO_HEADER_SIZE );
	$headerStr = substr( $server_output , 0 , $headerSize );
	$bodyStr = substr( $server_output , $headerSize );

	// convert headers to array
	$headers = headersToArray( $headerStr );	
		
	curl_close($curl);
	printr($server_output,'server_output','red');
	printr($headers,'returned headers','red');

And this is the JSON that I post:

[
    {
        "date": "2022-09-10T11:00:00",
        "date_gmt": "2022-09-10T11:00:00",
        "modified": "2023-01-18T18:10:59",
        "modified_gmt": "2023-01-18T18:10:59",
        "status": "future",
        "type": "sp_event",
        "title": {
            "rendered": "Bernex Basket - Lions de Gen\u00e8ve powered by Grand-Saconnex 1"
        },
        "content": {
            "rendered": "",
            "protected": false
        },
        "excerpt": {
            "rendered": null,
            "protected": false
        },
        "author": "1",
        "featured_media": 0,
        "template": "",
        "format": "league",
        "leagues": [
            109
        ],
        "seasons": [
            8
        ],
        "venues": [
            148
        ],
        "teams": [
            5391,
            6752
        ],
        "main_results": [],
        "outcome": [],
        "winner": 5391,
        "mode": "",
        "day": "",
        "minutes": "90",
        "results": {
            "0": {
                "one": "1",
                "two": "2",
                "three": "3",
                "four": "4",
                "ot": "OT",
                "points": "T",
                "outcome": "R\u00e9sultat"
            },
            "5391": {
                "one": "14",
                "two": "6",
                "three": "12",
                "four": "13",
                "ot": "",
                "points": "2",
                "outcome": "45"
            },
            "6752": {
                "one": "13",
                "two": "5",
                "three": "10",
                "four": "11",
                "ot": "",
                "points": "0",
                "outcome": "39"
            }
        }
    }, ... etc ... etc ... ]

Please help!