Baby congested only at night

Our LO will be 3 weeks tomorrow. Starting a few days ago, we noticed that he was getting congested at night only. He is so sleepy, but wakes himself up from his congestion every 30-45 min and as soon as we pick up him up and put him on our chest he immediately tuckers out. We have tried the breathe frida on feet/chest, saline + nose sucker, elevating his bassinet, getting a humidifier for our room, getting an air purifier, raising the temp in our room. Has anyone else experienced this? He doesn’t spit up, isn’t colicky, just congested overnight!