material problem

Hi all…I’m creating an arch viz project of an interior space. See screenshot, my problem is even though I have the same material applied to some geometry it gets very different results. Check the architrave (corner of the wall and ceiling), same material as the wall and ceiling but looks very dark, what am I doing wrong? Even the whole wall on the right is very white even though there is a window in the room on the left. All interior walls are 1 piece of geometry with the 1 material applied. I have done a preview and production light build with not much difference, changed the light map resolution and still have this problem. The scene has a sun, skylight, light mass portals, light mass volume, post process and interior lights. Any ideas?
Thanks.