When Tor connection fails, the previous tab url will be lost.

While retaining the session. When starting Tor Browser, TB will use the current tab to jump to the "Tor connection page" by default. When the Tor connection is successful, it will jump back to the previous URL.

When the Tor connection fails, it will not jump back to the previous URL. At this time, the previously opened tab may not be retrieved through "Return" or "History", causing the tab to be actually lost. If you happen to not save the URL, you may have difficulty finding the page you opened before.

I have experienced tab loss due to this problem many times. It brings me a lot of inconvenience.

The way I avoid it is to remember to create a new tab every time and then click the "Connect" button. But sometimes I forget to do this.

My suggestion is to always display the "Tor Connecting page" from a new tab, rather than leveraging the currently opened tab.