Facotl,
When using the VSG with the SA44B, you will probably want to start in real-time mode, or sweep mode with image / spur reject off (Settings menu). Then you can use a BPSK symbol rate of around 20-50 ksps. You should be able to see the modulation envelope, and measure the signal power using the channel power utility. Then you can go into modulation analysis and capture the symbols.
If you can send a picture, we may be able to help more, or you can email support at shnavloginupdates250428.kinsta.cloud for further assistance.