Raised multilingual here (as in father spoke one, mother spoke another, living abroad and US back and forth). I don't know about the stronger social ties but I have found that thinking in a different language helps me get to sleep easier. There are times when I'm spinning around in webs in English (work, life etc) at night, and when I switch over to Spanish thoughts I fall asleep easier.

Maybe just stuff like that is enough to make a difference.

That's nice, like the brain switching to "home mode" maybe?

Learned some french recently, heavy bouts of insomnia due to moving / stress - I will try this advice exactly this night.

Switching into another language also helps if you are stuck in an environment where you do not want to pay attention (e.g. on a bus with blaring ads that you can't mute or with a rude neighbor yapping on their phone).