gSender settings saved as .customization file not .json

Windows 11,
On my Win 11 desktop, when I export the settings from gSender Win 11 saves the file with the extension “.customization”.

Windows 10.
On my Win 10 laptop when I export the settings from gSender Win 10 saves the file with the extension “.json”.

If I change the file extension on the exported settings file from .customization to .json then I can import it into the Win 10 laptop and it works ok, so the file is actually a .json file but why does the Win 11 desktop save it as .customizaion?

@MartinC I’ve moved your question to the gSender Question category.