Why are my text messages not showing up on my iPad?
For iMessages to appear on both your iPhone and iPad, both devices need to be setup with the same Apple ID in the Messages settings. SMS text messages will not automatically appear on your iPad. You need to setup the Text Message Forwarding feature on the iPhone to have SMS text messages forwarded to your iPad.
Why are my Messages not syncing between my iPhone and iPad?
Make sure iMessage is enabled on both iOS Devices. You could check on your device in: Settings > Messages > iMessage. … Try turn off iMessage and turn it on again. If iMessage is on, Tap on “Send & Receive” > Select your phone number and email address that you want to sync to that device.