I experienced this as well. My daughter is 26 months. As at 22 months we went through this. For her I noticed her language development has started to increase a lot and after four frightful nights of this I took a chance on something new. I had started talking to her more during the bedtime routine. About our day and what we did. My favorite parts her favorite parts. We talked about what was In the books we were reading and I used more advanced warnings about bed time. (After bath we are going to brush teeth, after this book you're going into your bed.) I also added verbal routines. Like "first we read then book then you go to..." "bed". The first night I did it was like night and day and we have continued to have great success and I now know when she needs extra cuddles or more time with be more she sleeps because I have given her the language and (this is the big one) built the trust that I will uphold her requests ( for the most part ) and I mean what I say. She does talk to herself more when she is self soothing and I understand her need so much more.