30min naps usually mean baby is OT, and 45min naps can be either biological or not enough A time.
Questions:
Do you think maybe he is waking up earlier than you think he is??? That might make him OT for that first nap, I'm not sure.
Do you have a good wind down routine?
How are his night time sleeps?
How do you comfort him - pat/shh?
Has he ever taken good naps - you mentioned that nap times have gone mad - I'm assuming this is recent?
Does he use a paci?
That's all I can think of right now
Post back with answers, and we'll go from there!