When you add more ROOT to your current Nominated stake, it takes two Eras (Era = 24hr) to process, meaning that in the third Era, after adding to your current staked amount, you will see it reflected in your Active and earning amount.
Current Era: the task is queued to be broadcast to the Pallet during the rollover to the next Era.
2nd Era: the task is broadcast to the Pallet to Nominate the additional ROOT to your selected Validators.
3rd Era: the task is processed during the rollover to the next Era, and your Active and earning amount will reflect your full Nominated stake.