When I'm using Safari, it will eventually stop loading web pages. To be more precise, although Safari is not frozen (all menus work normally, no spinning wheel, etc.), when I try to load a web page it apparently starts loading (I get the blue progress bar in the address window) but the page never loads (the progress bar is always at about 10% of its length).
The problem persists if I restart Safari, even when pressing the Option key at restart. In fact, after this problem starts, pages won't load in Safari until I restart my Mac. It doesn't seem to be a network problem, since pages load fine with Firefox.
Background: I am running the latest version of macOS Catalina on an old (late 2013) iMac 27".
Some time ago I installed Sophos antivirus and Little Snitch, but I uninstalled them, following the procedure advised by the software providers some time ago.
