zero 4 fx fader very stiff-is this normal?

[driverdj2000]

my fx fader has recently become quite stiff,
there seems to be a lot more resistance than before.
it works fine but am worried its on its way out.
i know its not user replaceable.is it supposed to be stiffer than the channel faders?

[Graviton]

i just repaired mine due to a broken pin, can be done if you have patience and soldering skills.

not sure why yours is stiffer. I don't believe they take on that quality after time?