I don’t know if you noticed, but you’re in the German forum here.
Nontheless, the solution to your problem is simple:
it should work with the following macro:
It’s because there are some conditions for macros. If these conditions are met, the action will be initiated and the macro „stops“ at this point.
The problem with your macro was, that you put your Natures Swiftness before Regrowth, which always tried to activate Natures Swiftness, ending the Macro at this point (no matter if Nature’s Swiftness is on cooldown or not).
With the changes i made, it will first check if there’s an eligible target for your Regrowth (as indicated by the conditions „exists“ (wether it exists or not) and „help“ (checks if your target can be healed by you, won’t work on enemies)), if not, it will cast Nature’s Swiftness
Sorry for the late answer but yes I did. It kinda seems like the macro just instantly starts casting regrowth and therefore makes it impossible to activate another ability during the cast.