Leaky Fuel Filter

From my experience and the look of your photos the spring clamps are the first thing I would change. Cheap and easy.

As others have said your supply pipe from the fuel pump might have pinholes or a split. It is also simple and cheap.

Lastly, fuel line designed for fuel Injection, feels stiffer to me and the spring clamps might not be strong enough to apply enough clamping pressure.

Also be sure you have the correct size hose