Reopened/new Safari tabs close themselves?

Hi elweso99, We appreciate you reaching out to us. We understand that you are experiencing issues with a new tab closing by itself.

We’d like to gather additional details that may help us be in a better position to assist you. Does the issue seem to happen if the tab is meant to go to a certain website?

Does it help if you clear your Safari history?

In the meantime, we recommend that you check if the issue persists when signed in on a different user account. 

The article below can help if you do not have any other user account to test with.

Set up users, guests, and groups on Mac

If you are experiencing the issue when signed in on a different user account, we recommend that you check if the issue persists while on safe mode. 

Below is an article to help guide you through the process.

How to use safe mode on your Mac

Take care!

I have a similar problem. Here is the sequence: a tab in Safari for MacOS (on a 2017 MacBook Pro) is closed. It can be reopened by the keystroke Shift-Command-T. The tab reopens, but then closes all on it's own after a few seconds. Pressing Shift-Command-T will open up a previously, previously closed tab (not the one that you were intending on reopening.)

This also happens if reopening the closed tab from the History menu with "Reopen Last Closed Tab". It will reopen the tab, but then close it right away.