I started sleep training my daughter ( she’s 8 1/2mo) and we’re doing the Ferber method but less crying.. and we have a solid routine through out the day and for bed time

We have a sound machine, have bed time signals and everything .

After the 3rd night she started sleeping through the night in her room alone in the crib.

But now she wakes up 3 times through out the night crying so hard the worse we’ve ever heard since she’s been born. I go in there to comfort her and try and help calm her down but nothing helps her what so ever.

There hasn’t been any changes or any stress or anything that should disturb her sleep cycle...

Any advice on how to help her?? Or why she’s crying so bad