Greasy Fork

The toolbar on web snapshot pages (https://web.archive.org/web/.../https://...) is not displayed either before or after userscripts is installed. Pressing Alt and Ctrl at the same time did not help. Hovering the mouse over the top border of the web page also did not cause the bar to appear. Mozilla Firefox 128.0 (64-bit), Tampermonkey 5.1.1 (May 11, 2024), Microsoft Windows 10.0.19045.4598.

Sorry for the delay.

The script is not intented to display the toolbar, but to hide it when it is there (and if trigger the hiding).

I have only encountered your situation when javascript is disabled on web.archive.com either by an option of the browser or by an extension. Or if you have a userstyle set to hide the toolbar.

Achernar, this is strange, but the panel at the top of the page, for example this one, does not appear even in a private window with add-ons disabled. Moreover, this applies to both Mozilla Firefox and Google Chrome. My understanding is that this panel is no longer displayed on web snapshot pages and this userscript is no longer needed.

I still get it.

List of snapshots to choose from:
https://web.archive.org/web/20240000000000*/https://procyon-b.github.io/programming/

latest one: (the toolbar is on this one)
https://web.archive.org/web/20240416133324/https://procyon-b.github.io/programming/

See screenashot:

I still get it for the latest snapshot of old.reddit :
https://web.archive.org/web/20240723103241/https://old.reddit.com/

When you click on the cross in the upper right corner of this panel, after reloading the web page or opening another snapshot, does the panel appear again?

Yes, the panel appears again.

To be sure, I've even tested with my adblocker disabled.