Riven Values Wrong

[(XBOX)Mrddles]

I have a Gram Prime mod I bought in Maroo's. Looking at the mod in the mod station, it says +317.4% Crit chance (among other stats), but when I attach it to the weapon it says +231.5% Crit chance (all other stats are reduced as well). This is the case with all my Riven Mods (another Gram mod +14 toxin, attached +10; Rubico +139 Damage, +104 attached). I don't know why this is happening, but I would prefer to have the stats I paid for if possible, or find out how to get the full value out of these mods. 

[(XBOX)AeroTurner5150]

Weapon variants have different dispositions than their standard counterparts. Disposition affects the strength of the stats on a riven. What you see on the riven is the stats if you put it on the standard weapon (Gram or Rubico). However, the prime version of the weapon has a different disposition, so when you put it on that version, the stats change to reflect that variant's disposition. This is not a bug, this is intended.

The Gram Prime's disposition is a lot lower than Gram's since it is a very popular weapon, so of course when you put the Gram Riven on the Gram Prime, the stats end up being lower. The only way you'll see those stats you desire from that mod is if Gram Prime's disposition raises up to Gram's.