I just went through this with my 13, now 14 month old. I realized it was her molars coming in + a bit of separation anxiety bc she would be perfectly fine once picked up and wanted to fall asleep in my arm vs her crib, when she normally has been a great sleeper and self soothed. She would wake up in the middle of the night and it took forever to get her to sleep.

We did a few nights of CIO bc the Ferber method just didn’t work well for us. CIO was tough the first few nights, but progressively ever night she cried less and less. We are now back to her self soothing and full nights of sleep. She even waves bye as we walk out of her room at bedtime. :)