DFU error with NRF Toolbox

I have an MDBT42q module. Trying to update the firmware before loading my code.

I've made several attempts on iOS and Android versions to perform a DFU using the nRF Toolbox app (the only way I know how to update the firmware). I consistently get the following error.

"Error: DFU Service not found"

I've always updated my boards using this method. Any ideas? Here's a few things I've already tried.

• Reset bluetooth
  
• Tried different devices
  
• Tried iOS and Android
  
• Toggled on/off "external MCP DFU" in settings.
  
  

Thanks!