From being 6 months old my baby has been sleeping through the night, she's got a good routine that works but for the last few weeks she's been restless during the night, she will go bed without any issues but within a few hours of going to bed she will toss and turn and cry multiple times during the night, nothing in her routine has changed so I don't understand why she's restless, is there a sleep phase that babies go through at this age or could it be something else