QoL or Possible Bug change for RDM.

Quick question about Redmage and dual cast trait. Is sprinting suppose to cancel your dual cast. Potions also? Granted the opener starts with Verfire into Veraero and then pot on ogcd, but still, I don't understand why potions break dual casting. Also when you cast the first spell and dual cast is proc'd. If you sprint before you cast the 2nd spell you lose proc as well. I mean this isn't a huge issue but I noticed it tonight because I was late reacting to an ability that the boss was casting and need to get the hell out. I sprinted out of the aoe but then went to cast my verstone and I see 5 seconds... Once the raid was done I went to try it out on a dummy and sure enough sprinting/potions break the dual cast.

TDLR: Are sprinting and potions suppose to break dual cast procs?

I don't know if this is supposed to be but this is as it is already since before 5.0 - I somehow got adjusted to it but it is annoying.