Short Naps

My son is approaching his 5 month mark and is going through a phase of short naps. I can’t get him to stay asleep longer than 30 minutes for most naps and it’s starting to take up to 30 minutes to get him to fall asleep. He sleeps well overnight, this is just a napping issue. I also follow all of the tips to encourage naps (sound machine, sleep sack, dark environment) and it’s in line with his wake windows. Any tips? I’m not sure what else to try or what I can do to get him to stay asleep.