edge barrier from main to secondary display very difficult

Hello,
I have issue with edge barrier
I have 2 screen
going from secondary monitor to main is easy
going from main to secondary is very hard.

I have tried putting edge barrier to 0 / disable
it s now seamless from secondary to main, but still difficult (like 500px) from main to secondary.

How can I totally remove or better adjust edge barrier from main to secondary display ?
I run up to date Arch with KDE plasma

Thank you!