One possible reason is because you earned these trophies before you created your PSN profile and/or you were not connected to the internet when you earned them.
-edit. Nevermind. The above scenario is only an issue on the PS3, and possibly the Vita.
Last edited by COKTOE - on 27 August 2019- "If you have the heart of a true winner, you can always get more pissed off than some other asshole."