I standed on campfire and noticed that armor losses durability between hits (around 20 per second as there would be no cooldown). I don't think that is normal because on single player or vanilla server they lose durability only when you got hit, not between.

I checked as well fire, lava, magma block, cactus and sweet berry. Armor's durability still lose between hits.

Does anyone else has this issue on spigot server?