Weird shadow lines only when I look trough glass

Questions
1

I am seeing those weird lines in the shadows, but only when I look trough a transparent object.
See video, I am using react three fiber.

// the sun
<directionalLight
    name="Sun"
    ref={directionalLightRef}
    position={[-5, 10, 10]}
    intensity={0.3}
    castShadow
    shadow-mapSize-height={1024 * 4}
    shadow-mapSize-width={1024 * 4}
    shadow-camera-left={-10}
    shadow-camera-right={10}
    shadow-camera-top={10}
    shadow-camera-bottom={-10}
/>

// the glass material in the door
const glass = new MeshPhysicalMaterial({
    metalness: 0,
    roughness: 0,
    transmission: 1,
    wireframe: devToolsOptions.showWireframes,
    // @ts-ignore
    thickness: 0,
    envMap: glassEnvMap,
    envMapIntensity: 1,
    // color: '#e3fffe'
})

// the plane on which the shadow is cast upon
<mesh
    rotation={[-(Math.PI / 2), 0, 0]}
    receiveShadow
    onClick={clickHandler}
>
    <meshPhongMaterial color={'#656565'} />
    <planeBufferGeometry args={[50, 50]} />
</mesh>
2

Nevermind, was a classic z-fighting issue :smiley: