Did you try to put mode false in the acf part of block.json, not supports? So in your block.json, it would be something like:
{
"name": "your-block",
"title": "Your Block",
"description": "A dummy block",
"apiVersion": 2,
"acf": {
"mode": false,
"renderTemplate": "blocks/your-block/your-block.php"
}
}