What does it if you have an exclamation in red in iMessages
What is the red exclamation in imessgae
iPad, iPadOS 14
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The red exclamation mark indicates that your iPad cannot connect to the iMessage Service. A forced-restart will often resolve the issue - as may signing-out, restarting, then signing-in again to Messages in iPad Settings.
This support page may also be helpful in resolving difficulties:
If you can't send or receive messages on your iPhone, iPad, or iPod touch - Apple Support