Babyface, yep, it's normal for them to push out the dummy whilst sleeping. They say to not put it back in when sleeping.
Marielle got to a point where she kept waking up because she kept loosing her dummy because it kept falling out in her sleep. We then got her a sleepytot and it was the best buy ever! She knew her dummy was attached to the rabbit so she found the rabbit and then automatically her dummy. And we didn't have to get out of bed anymore!
https://www.sleepytot.com/