Currently Netro syncs every 1 hour. In the default mode, Pixie will go to sleep mode to save power after 5 minutes when it is manually powered on. Every hour it will wake up to check the latest watering schedules and report the power percentage. Therefore, when you start a manual run, the timer is most likely in sleep mode and it shows pending.
If you have to water instantly, you can go to Settings -> Timer-> "Keep Online" and enable the feature. Note the timer may start to keep online the next day and battery consumption will be faster when the timer is in this mode. Please refer to this article for more info: https://netrohome.com/en/shop/user_guides/2