PRIMALIST - DRU Tree re: Swarmblade Form - Serpent Strike

Switching to Swarmblade Form with Viper’s Call node active does not replace Armblade Slashes on the action bar with Serpent Strike. Zoning while in Swarmblade Form does.
Windfury Slashes node does not work when Serpent Strike has replaced Armblade Slashes.

It seems to have stopped switching to Serpant Strike on the action bar when zoning now. Perhaps a change in my weapon caused it?