Unable to correctly set / calibrate my curtain (ms-108rf / Zigbee)

Hi everyone,

I’m really new to HA, and I’m loving it.
After a successful test with a curtain and ms-108rf switch, I bought a small dozen of them to put on all my curtains. I’ve done 2 today, and I’m facing issue I didn’t had while doing the first on my test (beginner luck obviously). I’m using HA through RPI 400 and ZHA.
I’m unsure if I follow the correct steps. Right now one of my curtains doesn’t want to go up to the highest. It’s stucxl at around 50 cm from the “full open position”.
Could anyone give me some hints to configure that correctly ?
Thanks in advance,