Off the top of my head there are several possibilities .
1. An account isn't reporting to EQ
2. An old positive account has aged off of EQ but not the other 2
3. An old delinquent account has aged off of the other 2 but not EQ
4. A delinquent account has updated on EQ but not the other 2
The only way to tell is to pull your reports and compare them side by side
