Thank you for supplying pictures though another system. Sharing your pictures with other horticulturists we have some thoughts as to what is happening. First, Annabelle should only be propagated from a good known source and as cuttings. 1) The plants purchased came from the "wild source" (were Annabelle was orginally found) and not reliable over time. 2) Annabelle is not known to revert, yet that possibility exists. If that would occur, it wold likely come from a new stem coming off of the root system and not necessarily the crown of the plant. Follow the lacecap sytle flowers down to the ground and see where they are c oming from. 3) a comment really - All hydrangeas should be bought while in bloom to ensure that plants purcased are indeed what the plant tag says. while not an offical educational site the follwiong link may be of interest. http://www.hydrangeashydrangeas.com/identify.html
You may need to copy and paste the link into your browser for it to function. If additional information comes in I will make another reply.