Perpendicularity of four upper profiles

Hello. I have been printing for about a year, happily. Today I found/was reminded during a maintenance and upgrading, of my geometry of four upper profiles. Two opposite corners are perpendicular and the other two are not. I am wondering, if anybody has had a similar situation and if fixing the frame by tightening it while some profiles do not touch has worked? See pictures for hopefully understanding the issue... It is greatly exaggerated but hopefully the geometry principle will be clear.