I will give this issue another go.
Since whispers in the wall for me there is a bug where if I use my epitaph and than switch to my kronen, my frame just equips it with a hit as usual. However, if I stop melee-ing or trying to hit a tennokai, my frame just puts it awas with the old animation (prior to the swap animation changes.) and re-equips it.
I haven't found a solution to this problem yet.