Fix shutter core material that differs from the unit setting

Check the shutter panel's own core source when a shutter's core material in a pricing quotation differs from what is set at the unit level.

1. When a shutter's core material in a pricing quotation differs from what is set at the unit level, check the shutter panel's own core source.

   ✓ ১১ অক্টোবৰ, ২০২৬ তাৰিখে প্ৰডাক্টত পৰীক্ষা কৰা হৈছে

2. If the panel-level core source is set to Custom instead of Shutter, the panel does not inherit the Shutter Core Material defined at the unit (e.g. wardrobe) level.

   ✓ ১১ অক্টোবৰ, ২০২৬ তাৰিখে প্ৰডাক্টত পৰীক্ষা কৰা হৈছে