Lockpicking not leveling

I'm having trouble levelling Lockpicking. I have noticed that opening junkboxes with yellow text yields no skillups. Yellow should have a low failure rate, not constant.

Additionally, I am opening orange text footlockers in Outland and they are not giving me skillups. Orange should be a guaranteed skill up.

What's going on? Is this affecting anyone else?

Do you have skillpoints to lvl? sorry to ask but a guildie the other day was lvling lockpicking without realising they couldnt get it higher before the increased their characters lvl

I completely forgot about this part of the mechanic. Thank you for the reminder, I thought I was going crazy!