Annoying brake light glitch

[JTFG]

Well..
As the title suggests I've got a "glitch" with my brake lights.
Whenever you apply the brakes fast then the brake lights won't appear, or may flash for a second.
If you apply the brake lights a bit more gentle then the brake light will appear but once you apply the brake light a bit more then the brake light disappears.

I've already had replaced the "Stop Lamp Switch" but still the same issue.

Please help!

Thanks