Are you talking about creating a bookmark, or a shortcut?

Hold down the left mouse on the address bar icon, then move it to an empty area on the desktop, then let go.

On the page you want to bookmark, do a right-click in an empty area of the page. At the top of the menu, press the Star. Hot key; <Control> (Mac=<Command>) D.

Or, Press the bookmarks Star on the toolbar.

This will place a bookmark in the Unsorted Bookmarks Folder. To edit or move that bookmark, press the Star again.

A window will come up with the name of the page and its web address. You can edit these entries.

Next, select what bookmarks folder you want this bookmark in. If you do not see that folder, go to the far right of the Folder line, and press the down arrow. You can also create a new folder.

Click on the Tab and drag it into the sidebar.

That is the new control center 'i' button that has replaced the previously used globe/padlock.

See:

• https://support.mozilla.org/kb/control-center-site-privacy-and-security-firefox

If you hold down the left mouse button on the 'i' button and drag the mouse then the drop-down list shouldn't open. The doorhanger should only open if you release the left mouse button.

Start Firefox in Safe Mode to check if one of the extensions ("3-bar" menu button or Tools > Add-ons > Extensions) or if hardware acceleration is causing the problem.

• Switch to the DEFAULT theme: "3-bar" menu button or Tools > Add-ons > Appearance
• Do NOT click the "Refresh Firefox" button on the Safe Mode start window

• https://support.mozilla.org/kb/Safe+Mode
• https://support.mozilla.org/kb/Troubleshooting+extensions+and+themes