I've done some tests with SDI, I have less delay, but I still have a little. Can someone help me?"

Hi,

Changing the tracking delay in Aximmetry or the Calibrator should change when the tracked movement happens compared to the video, even with NDI. However, note that the delay you set in the Basic Calibrator is not saved in the calibration file. You will need to set it again in the Camera compound. For more details, please refer to this page: https://aximmetry.com/learn/virtual-production-workflow/green-screen-production/tracked-camera-workflow/inputs-tracked-camera/#delays

Note that the video or camera delay should only be adjusted if the video arrives before the tracking data, which is very unlikely to occur with NDI and Free-D. Instead, you only need to change the tracking delay.
If you notice delays only when the camera stops, it might be due to the PTZ camera's smoothing mechanism, which might not be represented in the Free-D data. If you can provide a video showing the issue, we may better determine if this is the case or if there is another issue at play.

Regarding remote connections via VPN, theoretically, they should work. However, please keep in mind that NDI is not designed for operation over the Internet.
Aximmetry has recently released a Gateway application intended to facilitate connections over the internet. It can also ensure that tracking and video data are synchronized, preventing varying delays from an internet connection. You can read more about the Gateway application here: https://aximmetry.com/aximmetry-gatewayhttps://aximmetry.com/aximmetry-gateway
Additionally, we have documentation of Gateway available here: https://aximmetry.com/learn/virtual-production-workflow/starting-with-aximmetry/aximmetry-gateway/using-aximmetry-gateway/ 

Warmest regards,