Blankets shouldnt be used right now, it can be a hazard for suffocation- use a sleep sack :)
We use a sleep sack, they work great!
Why are you trying to use blankets? If you're worried about warmth get a warm sleep sack and footie pajamas.
And remember babies don't need to layer much more than adults do. Right now it's so warm at night where I live my baby is in diaper under his swaddle for the first part of the night! 😊
I have been doing a blanket for crib naps during the day when I am watching on the monitor but he usually kicks it off when he is waking up. Try a sleep sack if you want it to stay on!