Sorry -- you already indicated you tried other browsers. Any common add-ons you have installed in all those browsers? It might be worth trying another browser that is just stock with no add-ons or altered settings.
Do you have any other devices on the same network you can use to test? If other computers or phones on the same network have the same issue, that might point to a common denominator such as an antivirus suite or a network problem.
I have heard of network problems causing images to not load correctly, but not for entire search results to disappear (other than the Darkreader issue, or an overly aggressive ad blocker rule).
Rebooting common network equipment such as a cable modem or an ethernet switch might be worth trying.
