Hi,

On my budget folder I got used to pushing the shifter a bit past
its detent to get a clean change going down. Going up worked fine.
Sometimes I just went 2 down, up 1, if pedalling hard uphill.

I set up the derailleur several times and it made no difference.
Set up for quiet running it was recalcitrant changing down.

So I thought its due to the shifter cable being mostly
housed and the friction / stiction that causes. So I
oiled the cables with WD40 (with a dropper).

That fixed it, ... sort of ... better but not perfect.
Still have to push the lever a little on some gears.

rgds, sreten.

Get the chain in first. Move the shifter to sixth. You
should be able to release both housings at the rear.