Manna Problem with Split Arrow

My wife and i played last night for the first time in awhile to check out the new patch and found that on both our bow rangers split arrow would completely stop attacking once manna ran out.
That is, it would not revert to default attack until manna was regained, we just had NO attack until we regained manna.
Tried a few different skills and key configurations and holding down shift when attacking, as one of the dudes on chat suggested, and found that it was only a problem with split arrow, and it was consistent despite changes in config etc.