If you encounter this issue it may be a desync between both software; Voicemod and Stream Deck.
To solve it, you can close both programs fully (from the system tray), initiate Voicemod first, and once you are able to transform your voice normally, initiate Stream Deck.
If after doing this the problem still persists, you should check if Voicemod, its plugin and Stream Deck are up-to-date.
If you have everything up to date, you probably have some software that is preventing the connection between platforms. Please, give the necessary permissions to Voicemod and Stream Deck to connect.
If you have started Voicemod first and then Stream Deck, you have everything up to date and you don't have any programs that are preventing the connection between Voicemod and Stream Deck, please try reinstalling Voicemod and its plugin.