My Conditional Actions become advanced actions ?

This happened like 5 times to me... I Always use variables to create checkpoints on the topics or buttons, so when my student visit them all Cp prompt them with a Windows with something like: Congrats, you've seen then all now to the next slide bla bla...

BUT: The conditional actions often turn into advanced actions and loose some of the actions I had programmed, making me do it all over again... (I have backups but its very troublesome to copy the slides, that causes some troubles of its own related to actions).

Does anyone know why does this happens? I understand that it  only happens when I keep making changes in my Project, but I Always try to leave the variables and the objects involved in the action untouched.

Just sharing and looking for some toughts