Not surprised. Nikon controls which batteries work w/ their camera. Ulanzi may wish that they work and specs might be compatible, but the Z 8 can test to see if the battery is genuine Nikon. A bit of profit grabbing from Nikon (to sell you more batteries) but also could be make sure batteries fully meet Nikon specs.I just got the Ulanzi batteries. They do not work with the Z8 despite they were also confirming when I asked them directly. Their website is still showing the compatibility with the Z8. I am pretty disappointed. I sent them a message, let’s see if they will refund me.
Slightly off-topic but very relevant. I had Dell desktop and connected several SCSI disk to it. At least once a day, often more frequently the desktop and disks would stop talking to each other. All within SCSI specs but ... I think wants to avoid situations like this