its because you are using the Renewal attack speed...
you disable it by commenting the line
src/config/renewal.h
// renewal ASPD [malufett] // (disable by commenting the line) // // leave this line to enable renewal ASPD // - shield penalty is applied // - AGI has a greater factor in ASPD increase // - there is a change in how skills/items give ASPD // - some skill/item ASPD bonuses won't stack #define RENEWAL_ASPD