Brakes seized up one minute then seems okay?

This happens when the brake booster push rod is adjusted out too far which does no allow the brake master to return fully holding the brakes on . To confirm the issue loosen the brake master mounting bolts 3 turns to see if the car starts to roll again, if so remove the master and adjust the booster push rod inward. Also a brake flex hose can come apart internally causing a short of check valve in the system but this is usually isolated to one brake either front or rear. Most common cause is a constricted rubber flex hose. That makes it hard for the brake fluid to release back to the reservoir. If you can get it to stay locked up long enough, open the bleeder screw on that caliper. If it releases, suspect the hose.