If you have followed the installation procedure. Make sure the SymplySPARK heartbeat light is flashing @ 1Hz (once per second), this will indicate that the controller is functioning as normal.
The SymplySPARK should be visible in the Apple System Information, System Report > Hardware > Thunderbolt
Check that the Thunderbolt cable is securely connected, and that it is a Thunderbolt certified cable, it will have the lighting logo on it. Likewise, if you are using a Thunderbolt 2 to Thunderbolt 3 converter it should be the Apple adapter, part number MMEL2ZM/A.
Also check that the Thunderbolt 3 port you are using is a Thunderbolt 3 port and not just a USB-C port. Note if you are trying to connect via a hub, it must be a Thunderbolt 3 hub connected to the computer’s Thunderbolt 3 port (check the port for a lightning logo) and not just USB-C.
Ensure that the correct driver for your macOS version is installed. Also ensure the driver has not been blocked from running by the macOS and the correct security settings have been applied.
Try re-installing the drivers.
Please submit a [support ticket] if you are still experiencing issues.
If you have any questions please submit a [support ticket]