dual mac 21.5s mid 2018 and one mid 2014 when connected with thunderbolt 3 to 2 adaptor and then pressing command f2 it works great but once i press it to go to sleep the additional screen doesnt work and isnt connected and goes back to just separate computer and not duals
iMac 21.5″, macOS 10.13
The question suggests two 21.5" iMacs set up to use Target Disk Mode, with Mid 2014 one acting as a display. The "Mid 2018" one (probably a 2017 or Retina 4K 2017 model) would be old enough to use another iMac as a display – though not old enough to act as a display itself.
Use your iMac as a display with target display mode - Apple Support
"To exit target display mode, press Command-F2 again. Or disconnect the cable, or restart either Mac."
When the "Mid 2018" iMac wakes up, and the Mid 2014 iMac is no longer acting as a second screen, the OP could try pressing Command-F2 again on the Mid 2014 iMac.
If that works, great. If not, I don't think Apple is going to be fixing any bugs in Target Display Mode any time soon.
Hey there!
What's your setup of connecting the two Mac computers?
Also, what's the exact model of the first 21.5-inch iMac? There was not a 2018 model.
Identify your iMac model - Apple Support
-Jack
Dual Mac 21.5s wont reconnect once put to sleep
