DIAGNOSIS The aluminum shoe (base plate) is likely warped from a drop or impact. It is not bending from normal use.
FIX Check for debris under the shoe. Remove it. Place the shoe on a known-flat surface like a granite counter offcut. Use a straightedge to confirm which corner is high. Do not attempt to hammer it flat. The shoe is a replacement part.
IF THAT DIDN'T WORK The pivot bolts for the depth adjustment might be loose, causing a twist. Check the two bolts that secure the shoe to the main body. Tighten them securely.
HEADS UP A warped shoe makes accurate, square cuts impossible. Replace it. Part number is typically stamped on the underside. Order the correct shoe for the XSH03Z.