Build not triggering on non production branches with latest commit

I have been facing an issue with the build. I have configured 2 branches for the build previews, one being the production branch, and another is a xyz/* branch.

So, the deploy previews are working fine with the production branch, but for the xyz/* branch(s) its not triggering the newer builds if I am pushing more commits to a merge request.

I quickly wanted to check what sort of changes i had to make in order to make this work or this is a constraints from product’s end?

What site are you seeing this on?