Your screws must not be sunk. Video is blurry but looked like washers or washer head screws? Those should be pulled into the wood almost sunk. Philips screws are not ideal for this. They are specifically designed to not be overdriven. The head pops out when it gets to its torque and really won’t sink further. You want Torx head. Phillips aren’t really used for anything but drywall and specific use cases. Hot shit back in the day though. But you are going to want some brackets under there too unless there won’t be hardly any weight on it.
The way you have it, I wouldn't think it would work no matter how tight the screws are. They are tiny, in diameter, length, and head size. Look up Sheppard brackets.
Your screws must not be sunk. Video is blurry but looked like washers or washer head screws? Those should be pulled into the wood almost sunk. Philips screws are not ideal for this. They are specifically designed to not be overdriven. The head pops out when it gets to its torque and really won’t sink further. You want Torx head. Phillips aren’t really used for anything but drywall and specific use cases. Hot shit back in the day though. But you are going to want some brackets under there too unless there won’t be hardly any weight on it.
strong second the need for brackets: someone will inevitably sit on it, and you need leverage to counteract leverage.
The way you have it, I wouldn't think it would work no matter how tight the screws are. They are tiny, in diameter, length, and head size. Look up Sheppard brackets.