Earlier today, Ubiquiti released UniFi Protect 2.8.28 which includes a huge list of improvements and bug fixes to the platform, as well as a few new highly requested features. First off, this update requires your UniFi OS Console to be running version 3.0 or newer in order to be able to install this version.
In terms of new features, Ubiquiti has now added auto-tracking on the G4 PTZ, which is limited to just people at this stage - even though the G4 PTZ can track vehicles. This camera has also gained support for more presets and home views. For the FloodLight, it can now turn on when a paired camera has a smart detection.
Lastly, the stackable NVR feature has been greatly improved, now allowing you to see which cameras are attached to each device and also move them between each NVR, if you need to do so.
Otherwise, there is a huge list of improvements, which you can find here on the official Ubiquiti Community post.