When the player is below max health, Rejuvenation modifies two actor values of the player:
- HealRate: health recovery out of combat. 0 by default. Rejuvenation increases this value when your are below max health.
- CombatHealthRegenMult: a multiplier applied to HealRate during combat. 0 by default. Rejuvenation increases this value when you are below max health and in combat.
[Health Regen in Combat] = [HealRate] * [CombatHealthRegenMult].
Rejuvenation Rank 1:
- HealRate = 0.5
- CombatHealthRegenMult = 0
Rejuvenation Rank 2:
- HealRate = 0.75
- CombatHealthRegenMult = 0
Rejuvenation Rank 3:
- HealRate = 1
- CombatHealthRegenMult = 0.5
Rejuvenation Rank 4:
- HealRate = 2
- CombatHealthRegenMult = 1
At rank 1, [CombatHealthRegenMult] = 0, your [Health Regen in Combat] = 0.5 * 0 = 0, you don't heal in combat.
At rank 3, [CombatHealthRegenMult] = 0.5, your [Health Regen in Combat] = 1 * 0.5 = 0.5, you heal in combat half as fast as you heal out of it.
At rank 4, you can do the math yourself.
So, what went wrong?
Upon combat starts, your HealRate is set to 0 no matter what.
As a result, your [Health Regen in Combat] = 0 * [CombatHealthRegenMult] = 0. You will not heal at rank 3 and 4.
The cause is unknown to me, but you can workaround it with a console command, since it's just an actor value.
The workaround
We use console command to add a HealRate value to our character, this added value is permanent and will NOT be set to 0 when you engage in combat, unlike the vanilla Rejuvenation script.
For rank 3, or if you already "fixed" rank 3 and are upgrading to rank 4, type:
player.modav healrate 1
For rank 4 directly, type:
player.modav healrate 2
Important note: modav will add the value to the current one. So if you already "fixed" your rank 3 and are upgrading to rank 4, just add 1. Otherwise add 2 for rank 4.
Keep in mind this is not a proper fix, it just makes your rank 3 & 4 rejuvenation work correctly in combat at the cost of incorrect HealRate out of combat.
Once combat ends and you are below max health, the game will add a HealRate based on your Rejuvenation rank to your character's base HealRate.
By applying this workaround, your base HealRate will be changed, but the game still adds to it regardless.
Therefore, your out of combat HealRate will be incorrectly increased, if you are OK with that.
Do note using console command disables achievements. I recommend Baka Achievement Enabler to counter this.