Slide left/right animation fail

Am currently designing an app to present to my client. The slide left/right animation isn't working consistently. Sometimes the only option presented to me is to dissolve. A solution that was working was to create a new artboard, copy all elements and links from the original artboard to the new one. After doing that, slide left/right became available. Then a new issue presented iteself. Even after designating slide left/right, the actual action is dissolve. To be clear, I've wired it to slide but when I peform in preview the result is a dissolve.