I usually play in third-person and when I activate my invisibility, I seem invisible, but when I start to move around, I become visible again (and become invisible again when stopped). Yet it always seems that NPCs can still see me. Guards will say something along the lines of 'Are you trying to hide?' when I am invisible.
I've tried everything. Save and reload doesn't work, multiple different potions didn't work. I even have the power 'Embrace of the Shadows' and that doesn't work. I've been wondering if it is my armor or weapons, so I took those off. Nothing. I tried muffling my footsteps. Nothing. I tried having no carry weight. Nothing. I am completely unable to go invisible. Guards and enemies attack me on sight, and this is becoming a real annoyance.
Is there any way to fix my problem, and does anyone know why it was caused?