I believe equipment also scales and stats are affected negatively as you level. I'm not sure how it works though, but I've read something about this before.
dtsv217_ESO wrote: »So I leveled a warden to level 50 (and thus my CP level) and as I gained levels I noticed that all my stats, health, stamina, regens, etc. kept getting smaller and smaller even though I updated my gear to match my level. Now that I hit level 50 I saw that they all took a pretty big hit downwards and my stamina regen went from 1600 to 800 with absolutely no changes in equipment.
Is there a boon to lower levels that is supposed to help them or am I getting a bug?