Why doesn't macOS Messages accept keyboard input until clicking inside the iMessage text field?

Hey TPEAN,

Welcome to Apple Support Communities. If this only happens in Messages, try the applicable app-specific troubleshooting from If an app freezes or quits unexpectedly on Mac. Steps there, such as restarting the app and Mac, may be all that's needed to resolve this.

• If an app doesn’t quit as expected or it’s unresponsive, you can force quit the app (you may lose unsaved changes). Choose Apple menu  > Force Quit, select the app in the dialogue that appears, then click Force Quit.

• If the app quit, reopen it by clicking Reopen in the dialogue that appears.

• Restart your Mac by choosing Apple menu > Restart.

• Make sure the app is compatible with your version of macOS.

• Open another file in the app. There may be a problem with the original file.

• Check for updates to your software.

• Disconnect any peripheral devices you just connected (for example, a printer). They may not be compatible with your version of macOS.

• Uninstall any app plug-ins or enhancements from other manufacturers.

If you recently updated the app or macOS, a plug-in or enhancement you installed may no longer be compatible.

•Diagnose problems with your Mac to learn whether hardware you installed, such as additional memory, is incompatible, improperly installed or defective.

Take care.

Thanks for the additional information, TPEAN. Let's see if we can get to the bottom of what may be happening.

When you set up a test user account, do you still notice this happening? Set up users, guests, and groups on Mac - Apple Support

Regards.

TPEAN,

Thank you for giving that step a try.

Have you had the chance to check if the issue persists on safe mode? Below is an article to help guide you through the process.

How to use safe mode on your Mac - Apple Support

Safe mode can help determine whether an issue is caused by software that loads as your Mac starts up.

After trying safe mode, boot up normally, then let us know how it goes.

Take care!