I have a quick question if you don’t mind. My messages between my phone and MacBook aren’t always syncing. Sometimes they are and sometimes not - this just started a few days ago. Any helpful tips?
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Messages can move between devices based on either your AppleID or your phone number. Making sure you have allowed for both is the first step to ensuring messages sync (with one exception I'll get to in a moment). Go to settings in Messages on both your phone and computer or iPad and make sure all are checked and that "Start new conversations from" is set to your phone number. Also, importantly, be sure that "enable messages in the cloud is checked" as seen below:


Finally, you may be aware by now there is a big difference between green and blue messages. Think of it like this, blue messages are delivered by Apple via your AppleID and iMessage. Green messages are either from Android users that don't have an AppleID, iPhone users that have never logged in to iMessage, or from a message that couldn't be delivered otherwise. Green messages are typically being delivered by the phone company and blue messages are delivered by Apple. (Generalization but you get the point). Thus, green messages have a hard time crossing over to AppleID only devices like computers and iPads. Since those devices don't actually have phone numbers, it then relies on Apple to sync them and that doesn't always go well.