K....boys need more cuddling than girls...so he might be suffering from tenseness which his sleeplessness brings on. (It is much easier to cuddle the happy baby!)
The daycare might have something to do with the problem. Though both likely are in the same dc, their situations could be different. Maybe the same thing as at home; a fussy baby doesn't get the cuddling that the 'easygoer' receives...AND THEY KNOW IT. Sadly, girls frequently are seen as 'cuter'; and, again, they get more 'comfort' holding...softer words, etc.
Look for these things. Also some eardrops may relieve any pain there. Even to wipe the entrance of the ear with a bit of Listerine on a Q tip can do great things. (I use that trick for myself when congestion makes my head uncomfortable. Great for colds, etc.)
Perhaps getting her to sleep first, and giving him a few extra cuddly moments might make him more at ease.
ESPECIALLY guard against letting yourself be irritated (it shows in the voice/handling) when he needs attention. ("THERE HE GOES AGAIN...disturbing our sleep"...can really bring out the worst in us!)
(I am Mom to nine...with nine younger siblings in my life. Even five that were older than myself. My mom raised 16. I stopped counting grandchildren/greatgrandchildren at about 30.)
KayMarie