Something is bent or 1 tire is flat

LR even Defenders and Disco's had the DS springs longer (when I did an OME lift with new springs I talked the shop into sending me all driver side springs so they were all the same length)
You need a long straight edge and level or a string level
I would start low (bottom of rims or bottom of portals) and then move up point by point until you find where it is level then not level