https://bugs.freedesktop.org/show_bug.cgi?id=93017
--- Comment #8 from polo lathanderjk@gmail.com --- I see you have same laptop as me zbook 14, DP on docking station are conected only to AMD GPU.
I have DRI_PRIME=1 issue with new kernel (probably start with 3.19) maybe is related
https://bugzilla.opensuse.org/show_bug.cgi?id=954783