Z6iii Flash Compatibility Problem?

2 I have a Nikon Z6iii. I bought a Flashpoint Zoom LI-ion R2 TTL flashs. The camera talks to the lens, Adjusts for range, and initially showed flash ready indicator on camera, but now the indicator is always red. The flash does fire. In dim light the AF beam worked first time out, but it does not now. The Nikon z6iii tells me that i cannot control flash from flash control menu. Is this a mirrorless issue with the camera and flash? The Adorama description said the unit was compatible with Nikon cameras, but the manual that came with it says compatible with Nikon DLSR.

I honestly don’t know what’s going on, also some of the functionality on the manual doesn’t match up with the unit itself

Any advice?

Edit: thanks everybody for the help! Appreciate it you’ve got me on track