Chromium from electrode not oxidizing in electrolysis
Some of the ways you aren't at standard condition.
Metal solution so the activity of the metals are at their concentration in the alloys 
The solutions have far below 1mol/L of their respective metal ions 
The oxygen that you are reducing in basic conditions is probably about 258 micromol per litre-
whereas it should be 1 mol/L. The potential might be too high- its hard to tell the solution resistance is an effect. 

If you were at standard condition with low voltage then the first experiment makes perfect sense-
From wikipedia full list of electropotentials
V2+ + 2 e−
    V(s)     −1.13

Cr3+ + 3 e−
    Cr(s)    −0.74
Vanadium is preferred.