Unfortunately this is not how it works. A get parameter does not take you anywhere on its own.
The WordPress system, and occasionally, some themes or plugins interpret your get parameters and can do anything they want with them, including redirect you. This is why I have prefixed the parameter with the plugin slug as is best practice (__wallets_faucet_ref). This ensures that the parameters in the faucet plugin is not used by other plugins.
Have you established that this is caused when that particular theme is activated? What happens if you switch to another theme?