If you have multiple Trackman iOs you have to make sure they are all set to their own unique frequency, 1-25.

1. Do do this, please open TPS
2. Navigate to "Settings" -> "Advanced Settings"
3. Select "About"
4. Click the “Show Device Web Interface” link.
   • This will open up a browser page showing the status page of iO
5. Select the "Login" tab. 
   • Click "Login" again, then "Force", and then OK.
6. Go to "Setup". 
7. Click "Frequency Groups". 
   • Here is where you can select the 1-25. 
   • Each iO must be on its own unique number. (TM4 frequencies do not overlap with iO)