Front Brakes Locking On After Car Idles.

Didn't touch brake system until problem arose and changed front hoses as it was suggested that they were collapsing. Bleed system until pedal was firm and had car on stands and rotated wheels by hand and applied the brakes to see when brakes would begin to engage.

Could be as simple as the master piston spring got weaker after use not returning the piston all the way.
This could explain the change, when nothing in the brake system was altered or changed.