@Robertofilho, I think something is wrong in your TRIGGERcmd agent's configuration. Uninstalling and re-installing doesn't delete the configuration. Please try this:Delete or rename your .TRIGGERcmdData folder in C:\Users\(your user). Delete your computer from your account. Close and re-run the TRIGGERcmd Agent. It will prompt you again for the token. Copy/paste that from the Instructions page in your account.
After that, you should be able to run commands again, and if you restart the background service it should stay running and you can run background commands.