There are a few reasons for failing to get a 3D FIX from your GPS dongles.

• Indoor obstructions. Test with GPS outside with clear access to the sky so that it can communicate with the satellites.
• USB3 Interferance: If the GPS antenna is is connected close to an active USB3 port (a USB3 port connected to a device like a camera), then the interferance may lead to failure in obtaining a fix. It's recommended to get a GPS dongle with a long wire away from StelarMate to protect against unwanted interferance.
• Incorrect baud rate: Some older GPS dongle uses a baud rate of 4800. The default baud rate in StellarMate is configured as 9600. Therefore, StellarMate would fail to communicate with the GPS dongle unless the rate is changed within StellarMate to match the GPS dongle rate.