I believe it’s because the layer you are trying to constrain is sitting under fixed scrolling position. I recall I encountered this behavior before

Thank you for your reply. It works for my case 😊😊. Additionally, besides the fixed scrolling, are there any other reasons behind this problem?

Hey @Linh7,

This is a bug that we’re already tracking, where the “fix position when scrolling” disables certain constraints.

We don’t have a timeline of when a fix will be available, but the best workaround in the meantime is unchecking “fix position when scrolling” before attempting to adjust the constraints.

Change the Scroll behavior to Scroll with parent.

Now the Left and Right Constraints are unlocked.

Revert the Scroll behavior to Fixed.

The Constraints will still remain Left and Right (Given that you want the element to be fixed while scrolling). Because that’s the only scenario when this bug pops up. And this seems to be a workaround until Figma fixes it.

well nothing works for me 😦