Hi there,
How many naps a day is he having?
Short naps are pretty common at this age tbh and some of this is developmental and they just grow out of it, not much help to you now i know but hope for the future!
45 min naps are usually UT so if you could maybe just post the last 2 days EASY even if it is not EASY as such then I can see what might be going on.
Is he sleeping in his cot for naps?