I'm not stupid... i would've noticed that. But let's say i have 18 Vigorous Healing Potions, i drink ONE of them and it unequips itself, leaving 17 more of them in my favorites menu without the hotkey number near it.
Sometimes they don't do this and i can keep using up all my potions... i don't really get it what's wrong.
Just started my second game a while ago.. in my first game I play a Nord so now I started a game with a Khajiit... and I'm experiencing somewhat similar problems, but with Iron items.
So during the very beginning of the game, I picked up 3 Iron Shields. Being the only shield so far, I favourite it and put it on my quickselect list and bind it to the number 5 key - just like I did with my Nord without a single problem for over a hundred game hours. But now if I press the quickselect key, 5 in this case, my character equips the shield, then I press it again, he unequips the shield. Press 5 again, the shield's no longer bound to "5" for some reason. Even though I never dropped any of the 3 shields.
Oh well, I sold all the Iron shields, bought a Hide shield, improved it with smithing to similar stats and it works just like it's supposed to.
Then, thinking I had resolved the weird momentary glitch, I smith myself a few Iron swords, planning on improving my dual wielding, which I didn't do with my nord.
I bind the Iron Sword to number 6. If I press it once, he takes one sword out, press it again, he puts the sword away, press it yet again; the Iron Sword is no longer bound to key 6.

So uh... any suggestions ?
I guess I need to try and drop the another Iron Sword and try if the quick "number bind" works normally when I'm just carrying one of such items.....
brb.
Edit: Yeah, if I'm only carrying one Iron sword, it works. He equips and unequips no matter how many times I press that particular number..
But it can't be a problem with dual wielding, as the game did it when I was carrying 3 Iron shields...
Damnit, so frustrating, as I just got used to quick equipping all my favourite weapons from the keyboard numbers...