First the parents will gather them back up in their mouths and spit them back out onto the vertical surface.
But eventually, they will no longer adhere and will begin to swim freely.
Here is a video of Papa Lindsay Buckingfish gathering up popped-off wigglers and attempting to put them back where he thinks they will be safe.
When they no longer adhere, they should begin eating live brine shrimp - just about the only thing that will fit into their miniscule mouths!