life steal stops working on occasion
sometimes lifesteal just stops working for no reason. hit a minion, crit and no heal, crits are generally easier to tell. but im assuming its all around
2 Comments
There is a minimum heal threshold for the healing value to display (not sure what it is, maybe something like 20?)
So if you crit, you deal more damage which in turn makes you heal for more which also likely is above the display healing threshold, which is why you only see it with crits.
My assumption is that you are still healing, but the value is too low for it to display (but your health will still go up)