Is it just green/teal that have messed up server ticks?

[Widan]

It's the second tick that brings your health and mana back down. First tick is too much, second tick corrects it. When you are real low level you won't be able to tell from the mana bar, so look at health numbers instead. Once you are 20+ you should be able to see the mana correction.

Wait for the correction before you stand.