x axis in i3 pro C

[didou72]

hello
i have a i3 pro C
I have a lag on the x axis during printing. the belt tensioner was very unclamped , but he always moves vertically. I greased the two axes, but it always shifts .
is that the belt has to be very tense or not? I stretched the belt during printing , and I also had a mismatch.
how can i solve problem??
please help me

[Admin]

can you post a photo of your X axis belt