I’ve seen the rubber flex hoses fail and not release the pressure from the calipers.I’ve seen this happen more then once but never both at the same time.
Same, and in my case both front wheels did fail around the same time. Car had sat for about 10 years before it was out back on the road. Figure the weather took its toll and hit both sides just as hard.
Even with the issue fixed, replacing old lines is probably prudent.