Maybe try some quiet sleepy time music instead of the sound machine. My grandsons go to sleep with that easily. It's worth a try but don't leave it on all night so they can sleep without it.
Also they may just need time to learn to go to sleep quicker again as this is all new to them. Don't give up you're doing a great job.
Updated
Maybe try some quiet sleepy time music instead of the sound machine. My grandsons go to sleep with that easily. It's worth a try but don't leave it on all night so they can sleep without it.
Also they may just need time to learn to go to sleep quicker again as this is all new to them. Don't give up you're doing a great job.