So I was playing the other day and realised that I couldn't notice my sheild quite well and I had actually equipped it.So I went online to see why it was happening and I was playing on my single player world with no mods. After a while browsing online i found the reason, whenever a cape is equipped,the sheild appears to be extremely low on the screen like it can't even be noticed sometimes and even when crouched it appears lower than usual.