I have one form type (extending AbstractType) which has an option to switch between adding children either as regular fields or as hidden ones. Two instances of that type are created in the controller, one with regular fields, one with hidden ones. Both instances are passed to the template. The form with hidden fields is rendered first, then the other one.

That used to work well. But with #4918, the 2nd form isn't rendered at all. I couldn't find out why, as isRendered() still returns false prior to being rendered and it also has() all expected fields. Both forms would also be rendered correctly when changing their order.

@bschussek: Do you have a clue what could cause this? Or shall I provide some of the code mentioned?