I want to use my late 2012 iMac as a second display for my work laptop which is a ZBook G3. I bought a genuine Thunderbolt 3 to Thinderbolt 2 converter and a Thunderbolt 2 cable. I've updated all software. When I connect the device's I'm unable to initiate target display mode using the normal CMD-F2 command.
I'd really appeciate any advice on how to solve!