Took the HK out today to do some cleaning and checking overall operation. After taking it apart and racking the slide a few times a small metal piece came out. After looking on the internet it appears my flat spring broke. Now the trigger still works and hammer operates but I am unable to have it cocked and locked but the decocker still works and everything else is normal. Is this a normal occurence over time due to wear and tear or ??? Any help would be appreciated.