Please provide more information to help us understand the issue:
1. Are you using TypeKit fonts in your project? If yes, then issue is when your device connects to to your computer as the websever, Typekit does't see you computer as an authored user of your fonts. The devices ins't connecting to "localhost" but using whatever the ip address of you computer is on the network. If you want to preview the fonts you either need to add your computers IP address to your kit settings or put the preview up on a server that your kit allows.
2. Are all the application components running on the same Subnet?
I've got it figured out...
Initially when I was trying to view my reflow project through edge inspect, I would have my phone connected to Chrome through the Inspect plugin. In Reflow, I would click View --> Preview in Chrome and all I would get was a blank screen. If I connect my phone to Reflow through the inspect tool there, it works fine.
Is there an issue with the Chrome plugin?
Glad that it worked!
View --> Preview in Chrome generates the URLs as localhost which will not be recognized by the devices. For Device preview recommended approach is to use Inspect extension then the generated URL is formed from IP address and therefore will be accessible to other devices as well in your local network.