PC Berserker passive resist boost

[Veny]

Heyah,
My Zerk has 10% resist on level 13, but he should be getting only 2% resist each 5 levels (so he should have only 4% resist). Is it a display bug of bonus formula, or final boost, or something else entirely?

 

[Hoors]

I was just about to post about this. Resist has been at 10% since level 6 (which was my level during the rework).