Armor Bars don't get displayed after death using the attribute generic.armor. For e.g. Using /attribute Tigerhint minecraft:generic.armor base set 100 then dying due to fall damage which does not get negotiated you don't respawn with the 10 armor bars you would have if you would wear netherite armor. 

It only shows again after updating it with commands (minecraft:generic.armor base set 1 for e.g.) but you still have the attribute.