Unhooking yourself freely from face campers. I think this is becoming a problem a lot.

It's end game phase so this is expected behavior. At that moment your team mates must rescue you. No free unhook.

What is problematic here is when killer tries to camp like that but your progress bar doesn't move because another survivor tries to rescue you.

A hud should display your camp bar to all other survivors so they could know if you are camped and stay away from you, essentially allowing this anti-camp mechanic to work. In SoloQ, it often never works because of miscommunication which allows killers camp when there are multiple gens because survivors swarm the hook and disrupt the progress of the bar.