scope: declarative pipeline + bitbucket multi branch

for optimization purpose (big repo), i chose to skip the default checkout.

        options {
            disableConcurrentBuilds()
            skipDefaultCheckout(env.PR_NUM != null)
        }

i also implemented my own checkout, depending on branch's type (feature, PR-,...)

pipeline triggers jobs on every commit i do, but somehow the "changes" are not caught

when i do NOT skip the default checkout, everything works as expected.

Question: is this as "per-design", how can i get rid of this issue?