Did you try to have two different quivers- in one diamond arrows then in second crystalline and to put quivers on hot keys instead rather than of arrows ?
Quivers were created to help you to organise your ammunition - if there is an issue with it- it must be reported as a big.
bug.
Secondly-did you imbue your bow with elemental damage? Please note that elemental damage which imbu does not work with diamond arrows ? arrows. That would explain why it ignores diamond arrows.