The Z6 and Z7 went to firmware 3.11, which is a fix that relates to use of the MB-N10 Battery Pack, which was not properly switching batteries sometimes.
However, Nikon also put a warning out: version 3.1 and 3.11 of the Z6 and Z7 firmware have a known problem related to AF Fine Tuning. Apparently Saved Values are not being appropriately applied. Nikon says they are working on a fix for this.
Thus, if you're on version 3.0 of the firmware, I'd say wait for the next update. If you're on 3.1 and not using the MB-N10, I'd also say wait.
