I understand you are having issues with the wrong channel coming up once you have selected it through the guide. This sounds like you have the wrong channel line up, you can try and process a reconfiguration to see if this gets your issue resolved. All you have to do is go into your Slingbox settings and reconfigure the input source. There are different ways of re-configuring your Slingbox. This really depends on the device that you are using and the Slingbox model. Please review the links below for further troubleshooting steps:
Sling Media Support Team!