Safari undo close tab sometimes not works

Our apologies for any confusion, Andy20051996.

We're glad to know you're able to reopen a closed tab successfully. As for why a reopened tab closes unexpectedly, we'll want to look in to this issue further. While the title of the following article outlines a different issue, the steps included in that resource can be helpful in resolving the issue you're facing. You can also find these steps listed below.

• "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 dialog that appears, then click Force Quit.
• If the app quit, reopen it by clicking Reopen in the dialog 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."

If an app freezes or quits unexpectedly on Mac

Let us know the results after completing those steps, have a great day!

Hello Andy20051996,

To help resolve this issue, follow the steps from the article "Use tabs for webpages in Safari on Mac":

Reopen a recently closed tab

• In the Safari app  on your Mac, choose History > Recently Closed, then choose the webpage you want to reopen.

• You can also reopen a closed tab or window.

Best Regards.

I had the same exact problem on my late 2013 MBP, and thought it would go away when I upgrade but its still there as you said in the M1 MBPs as well!