Hi and welcome to the forums
First of all, I want to say that we don't support CIO at all on this site as Tracy believed it broke the bonds of trust between a LO and its caregiver. We're here to find more gentler ways of sleep training. I hope we can help rather than you resorting to that. No, I'm sure we can help, that's a better word!
For some yes, a 30mins nap can be OT but I'm actually thinking yours might be UT based on your routine hun. 2hr A time is a good starting point but actually more suitable for around a 4mo if you see here
Average A times- BOOKMARK ME! I think we need to be looking at closer to 2.5hrs considering he took a better nap after a 2hr A time after a short nap where normally we'd look at reducing the A time slightly after a short nap.
I would extend to 2hrs 15mims and hold for a couple of days and see if that helps with that first nap. It might not at first, but we will get there ok? We'll just take it nice and slowly until we find the right A time for him. If we jump it too quickly then he may get OT and we won't see it until it's too late.
Do you want to try that tomorrow morning and let me know how it goes? Then we can take it from there. ((Hugs)) in the meantime, short naps are the pits. My DD short napped for months until we sorted it out with help on here. At least you're getting one good nap so far so you know he is capable
xx