Warden - Green balance skill line slow levelling

SP1K3S

I just got my warden to level 20, and I am enjoying it. Ever since I got my first 3 skill points I have kept 1 skill from the ice and green balance skill lines. I have not had any more than 1 of those skills at any time.
I have not slotted a second weapon with my focus on levelling specific skills and don't want to accidentally be on the wrong bar when handing in a quest.
So far I have only been completing main story and guild quests and killing anything in my path.
My green balance skill line is falling further and further behind the other skill lines. Right now almost 5 levels behind.
My understanding of how these level is that they just need to be on your active bar at the moment you earn xp. So I would have expected these 2 lines to be very close to the same level.

Dixa

I can confirm the skill line levels slower than the other two.

I have had two green, two animal, one winter one destro staff on at all times. winter and animal are the same level (winter should be LOWER) and green is a good 3 levels behind - animal and winter at 43, green at 40.

SodanTok

Yeah, can confirm that too.
I had 1 green balance skill on my main bar since lvl 2 (still have it, 2 days after getting to lvl50), most of the time I also had one green balance skill on my backbar (and still have). Im now on lvl 49 of green balance.
I had 1 winter balance skill only most of the time on my main bar since lvl3, rest of that time including now it is on backbar. Maxed the skill line 2 days ago.

Mojmir

Confirmed

majulook

yep, its excruciatingly slow I even started spamming a couple of its skills it at several dolmen's cold not tell if it increased the skill lines or not.