Clicking on a previously read message to make a response makes it disappear

Thanks Hoffmnron,

Are you using Messages in iCloud on Mac? Here is how to check: Set up iCloud for Messages on all your devices - Apple Support

Also, if you restart your Mac do the messages reappear? Let's try that next. Here is how: Shut down or restart your Mac - Apple Support

Let us know what you find.

Cheers!

Hey Hoffmnron,

We understand that you're having trouble with messages on your Mac. We'd like to gather more details in order to help.

Which app is this occurring in? If it's a third party app, do you have any app updates available? Use the App Store to update apps on Mac - Apple Support

Is this is occurring in the Messages app? If so, are you using Messages on another device? Do the same messages that disappear on your Mac also disappear on your other devices?

Let us know! Take care.

Hey Hoffmnron,

Does it happen if you restart in safe mode? Here’s how: How to use safe mode on your Mac - Apple Support

Depending on the type of Mac you’re using, be sure to follow the correct steps to restart in safe mode. We also want you to be aware that restarting in safe mode may take a bit longer than usual since it prevents some software from loading and does a check of your startup disk. You may also see some graphic anomalies on your screen as well.

Once you’re in safe mode, test the issue. Whether or not it happens in safe mode, restart normally to exit.

If the issue didn’t happen in safe mode, try again after the normal restart.

If the issue happened while in safe mode, or reappeared after a normal restart, we recommend contacting Apple Support to look into this further with you: Get Support

All the best.