Currently, the error seems to be fixed, so I don't think there is a big problem writing Opera.
The biggest reason to use "Reopen Tab" is when you accidentally reopen a closed tab.
But now when checking for errors, it has been changed to reopen the last closed window or tab instead of reopening the window first.
My current version is 76.0.4017.123, so I'm not sure if the error is fixed.

Sorry for writing the translator
This phenomenon occurs once you start closing the window.
When a symptom occurs, "Reopen Tab" will not work, but "Reopen Window" will work to open the closed window. And if you close the window multiple times, "Reopen Window" works like "Reopen Tab". When you reopen the window you closed the first time, "Reopen Tab" works again.
The bottom line is that "Reopen Tabs" only works in the window you opened the first time.