In the Synapse Customize tab for the Naga V2 Pro, there are 4 pictures, 3 represent the 3 different side button panels you can have installed. The one currently installed has a green check mark, however if you change the panel out on the mouse the check mark does not move to the newly installed side panel, it stays on the one that was installed when Synapse started. You have to restart Synapse for it to recognize what side panel is installed.
Razer Naga V2 Pro, Firmware Version 1.3.0.0 (latest) on the Mac Synapse 4 Preview Version 4.0.86.2504290730, on MacOs 15.5.