Nikon Z8 Reference Manual page 85

19
Take pictures.
A k icon appears in the master camera shooting display
together with the number of remote cameras connected.
Pressing the shutter-release button on the master camera
releases the shutters on the remote cameras.
D
Connection Errors
In the event of remote camera connection errors, the remote camera count in the master
camera shooting display will turn red and instead show the number of remote cameras that
failed to connect.
85
Changes to Synchronized Release