Nikon released firmware update version 1.20 for the Z fc mirrorless camera. Here is the changelog:
Added support for NIKKOR Z 28-75mm f/2.8 lens
Increased the refresh rate for the focus point displayed during face/eye-detection and subject-tracking AF.
Fixed the following issues:
Pictures would be underexposed if taken at shutter speeds of 1/250 s or faster with a flash unit (other than the SB-5000) compatible with auto FP high-speed sync and 1/200 s (Auto FP) selected for Flash sync speed.
When assigned Zoom on/off via AE-L/AF-L button, the AE-L/AF-L button could not be used to zoom in on the display while the shutter-release button was pressed halfway.
The new firmware can be downloaded here.