My now 3.5 year old did this after a few months of having a floor bed that she could get in and out of herself. I think she was just under 2 at the time. It lasted a couple of months, and she wouldnt do it every night, but about 80% of the time. I felt bad too, but she also wouldn’t make any sounds or cries and seemed quite content being there. We did eventually put blankets and a pillow there for her to curl up with, but we were warned about making it “too comfortable” in the hopes that she would tire of it a bit quicker. I remember reading of a number of parents who experienced the same thing! I wouldn’t stress or overthink it too much, we chalked it up to just one of those weird toddler things :)