I have created a simple title with two layers .
1- Layer1 include a textbox
2- Layer2 include a rectangle and set as hidden while transition in and out
3- Appears of second layer set to Page 1 (Fly)
4- transition out of second layer set to page 2 (reverse Fly)
When the textbox in Layer1 have not any animation while datachange in , all works well . But:
When I set an animate in Datachange in or out for textbox in Layer1 , And run page 1 (appears layer2) then run page 2 (disappears layer2) , every changes in texbox will return the hidden Layer2 again .
attention: Its happen only when main layer objects have at least 1 datachange animation .

Its not possible to set Layer2 as hidden for Data changes.

I think its look like a bug .