After creating invisible armor stand (which is indestructible, unlike invisible frames 🙂) i have to /kill it. By mistake i destroy all armor stands. Anyway after that my shining armor lost it glow. I have to look at it at certain angle to see - to my surprise - two different types of glow. It also apply to magic items (golden apple, magic bow) in frames (all at once - same glow).
BTW. Everything in equipment works fine (armor i'm wearing or holding is also fine)