Hi Carl
I suspect that when you hover the mouse over the padlock it does not lighten in color nor is it active (you ought to be able to click on it to reveal the security certificate supporting the secured page.
Those certificates are retained in your Keychains folder. If the above is true, via the Finder, go to the Applications>Utilities folder and open Keychain Access. Once open, go to the Keychain Menu and select Keychain First Aid. Select the "repair " function. When done, close Keychain Access and restart Safari. Enter the URL for a secured site. Any change?
If not, quit Safari. Back to the Finder. Your User Account>Library>Preferences folder. There, move the com.apple.safari.plist file to the desktop, then restart Safari. This resets your Safari Preferences to their default setting. Try the secured site again. If no go, quit Safari and move that file on the desktop back to its original location, replacing the newly created one.
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