When I was playing on Minecraft and mining, when I was mining some obsidian and fell into lava with some almost broken armor, the armor broke yet the armor bar GUI was still there, just empty. The screenshot attached is what the armor bar looked like after the situation. This is classified in my opinion as a minor, visual bug.
Steps to Reproduce:
/give @s leather_boots 1 64
Equip the boots
Place lava or spawn a hostile mob
/gamemode s
Take damage from the lava or mob
Observed Results:
Armor GUI still shows when armor breaks.
Expected Results:
Armor GUI should disappear.
Can you make sure it's not the texture packs your using is causing it?