Clavinet "sticky" key brushings Question

[nonplus]

Hello,

please excuse my bad english explanation. My E7 plays fine when applying the force to the keys from the top.
But if I play e.g. "wider chords" / apply a bit of force to the sides of the keys, the action becomes sticky/slow.
I tried changing a single key brushing with a new one from vintag-vibe: same problem.

It feels like the brushing acts like a "break" to the side of the key. Should I just replace all the brushings?
Is this the "normal" behavior of the clavinet keyboard?

Thank you