Some dogs have a little fwip that's cute I'm not sure if that's what you mean or if they actually fold. If they flop at all I'd say keep posting or if its just the very very tips maybe try the breath rite strips.
They go on the inside of the ears but if the rest of the ear isnt done I would keep posting. If the whole ear is completely firm except the ABSOLUTE tippy tip then maybe breathe rites. But you should generally post for 2 weeks past when you think the ears are done anyway.