[Bug] Dual Wielding weapons of same name

I am dual-wielding 2 runic hammers, tried the recommended macro

/equipslot 16 Runic Hammer
/equipslot 17 Runic Hammer
/equip Felsteel Reaper

and all it keeps doing is swapping the hammer in my mainhand and my offhand never gets a runic hammer to wield. Is this a bug?

I tried changing the macro as follows

/equipslot 16 Mining Pick
/equipslot 17 Runic Hammer
/equip Felsteel Reaper

and it works,..which leads me to believe there is some bug involved with either...
A. dual-wielding weapons of the same name
B. dual-wielding a pair of runic hammers

Does anyone know a fix or can confirm the issue?