Tooltip bugs: Every DoT effect with an instant effects lasts 1 tick less time than fully

For example red buff, it says that it deals damage over 3 seconds with 1 tick dealing damage each second. In reality it deals 1 tick of damage instantly, 1 over 1 second, and another after another second = 2 seconds for the full damage.

Same thing for Font of Life. Heals for 55% instantly. 15% after 0.5 seconds, 15% after another 0.5 seconds; 15% after another 0.5 seconds = 1.5 seconds. I can keep going like this forever. E.g Ignite lasts 4 seconds instead of 5. Why? since it deals the damage instantly + 1 tick every second = 5-1=4