Mac no longer detects external display via Thunderbolt/HDMI adapters
I used to have an external monitor via Thunderbolt HDMI adapter, but I reinstalled the OS and now it won't recognize an external monitor at all. Tried troubleshooting and Apple article on external monitors, nothing. Help!
iMac 2011, 10.13.6 High Sierra
iMac 21.5″, macOS 10.13