Hi Sparks0007,
When it comes to your message disappearing, do you have multiple devices which you check your messages? If so, see if you have Messages in iCloud turned on in Settings > [Your Name] > iCloud > Messages. If this is on, what to do to one device happens to another. So if you delete a message on another device, it will also delete it off of your current device. Learn more about this feature here Use Messages in iCloud.
If you are not receiving the messages at all, review If you can't send or receive messages on your iPhone, iPad, or iPod touch.
Furthermore, from this article, in regards to having green messages:
If you see a green message bubble instead of a blue one, then that message was sent using MMS/SMS instead of iMessage. There are several reasons for this:
- The person that you sent the message to doesn't have an Apple device.
- iMessage is turned off on your device or on your recipient’s device. To check if iMessage is turned on for your device, go to Settings > Messages > iMessage.
- iMessage is temporarily unavailable on your device or on your recipient’s device.
When it comes to your notifications, see Use notifications on your iPhone, iPad, and iPod touch and review your settings:
- Check your alert style following the information under "Change alert styles"
- Check if your notifications are grouped under "Change group notification settings"
- If this is happening from the Lock Screen see "Change how notifications appear on the Lock Screen"
Hope the helps.
Have a good day.
