Son won’t nap longer than 45min


My LO will be 5 months old next week. He sleeps great at night - 7pm ish until 7am or later. I can’t seem to get him to nap for longer than 45min though. I’ve tried keeping his blinds closed, keeping them open, putting him down as soon as he shows he’s tired, and trying to keep him up a bit longer. Nothing makes a difference! It’s not from a wet/dirty diaper and he doesn’t eat right when he wakes up either. I know he still needs more sleep through the day than what he’s getting. I’m not sure what could be the issue or how to help him nap 😫 any ideas/suggestions would be greatly appreciated!