what is that weird shadow?

@Frn0731 is there a platform directly under that spot? I seem to recall that was an issue. Try raising the wall height & see if it helps.

@Starfree Yes thankyou , not sure about the platform but raising the wall height helped.
Oh I see now , yes there is a platform downstairs.

@Frn0731 I had this problem when platforms came out. Took me a while to figure out that since raised platforms increase height anything on it, if tall enough, will create a shadow on the floor above it because it almost pokes through. And glad it worked ?.