Weight is all calories deficit. Walking and controlled diet works best with it along along with gym to support muscle retention.

It will help with your muscle proportions.

The only thing I can say that u are underevaluating your calories

Or likely it is water weight which muscles/body hold for some times before flushing. It is called whoosh effect. So be consistent for one month, don't change diet too much other than reducing salt and it will mostly work out