sts please explain arlor pot stats bug

[archerdrake]

i have both normal dex gemed ring arlor pot lvl 41 and archon pot lvl 41.
i have 610.5 dmg on archon pot but when i switch to myth arlor of pot instead of
adding 3.5dmg to make 614 on my stats it will decrease to 603.1dmg.. hows dat happen??
sts please do explain this to me

[Madnex]

Arching rings have a damage or crit or armor bonus. Yours probably has the damage one.