Have a GS HP/100% Fort Necklace.
Every couple of minutes I go to Character Panel and my fort is listed as 0%. Have to change out necklace and change back to get Fort back to 100%.
Also, reset enhancements today, and wasn't able to select Racial Toughness 3 on a Level 22 Human.
Also noticed that the requirements information wasn't there when you hover over enhancements. I spent 76 AP so I assume that was enough to take Toughness 3.