Can't deploy built solution to one of the two HoloLens headsets through Wi-Fi

This is the same question as this forum post here, but reworded to prevent spamming.

I don’t understand why my solution is not being deployed to a HoloLens headset that’s connected by Wi-Fi, even if it’s on the same network as my laptop where the deployment is made.

Connected to an unsecured Wi-Fi network, one of the two HoloLens headsets can have apps be deployed by Wi-Fi or by USB… The other one, though, can only have a solution be deployed to it by USB.

Why can’t I deploy my Unity project to the HoloLens that can only have a solution be deployed to it via USB? In the Wi-Fi Properties group on the Advanced Settings pane for Wi-Fi, both of them say the Wi-Fi type is 802.11ac.

Are there any files or settings on the Windows Device Portal that would restrict one HoloLens from downloading a solution I’m trying to deploy? This is something me and my partners have been trying to figure out for the past three months.

First impression was that the Wi-Fi network may be too slow. But then it wouldn’t be possible to deploy the solution to one of them. Second impression was that there’s something wrong with the Wi-Fi dongle in the troubled HoloLens. However, that would mean it wouldn’t connect successfully to the network at all. And now, my impression is the connection settings has something that’s restricting it from loading the app being deployed through Wi-Fi.

I don’t know if resetting the HoloLens to factory settings is going to solve the problem.

On the Visual Studio 2017 Build Window:

On the Visual Studio 2017 Build Window:
Error DEP6957: Failed to connect to device '<CONFIDENTIAL_IP>' using Universal Authentication. Please verify the correct remote authentication mode is specified in the project debug settings. COMException - The network event being waited on triggered an error. [0x8007274C]  SharedHolograms
The IP address I wrote in the Start Options pane for the solution's Debug Properties does match the IP address that's shown in the Wi-Fi Properties pane on the HoloLens, though. Something I didn't point out was that on the other HoloLens, it's able to accept incoming apps from Visual Studio in Universal Authentication mode.

The IP address I wrote in the Start Options pane for the solution’s Debug Properties does match the IP address that’s shown in the Wi-Fi Properties pane on the HoloLens. On the other HoloLens, it’s able to accept incoming apps from Visual Studio in Universal Authentication mode.

I tried out the two other authentication modes I have as well: Windows, and None. No success, but some error output:

Error: Unable to connect to the Microsoft Visual Studio Remote Debugger named '<CONFIDENTIAL_IP>'.  The Visual Studio 2017 Remote Debugger (MSVSMON.EXE) does not appear to be running on the remote computer. This may be because a firewall is preventing communication to the remote computer. Please see Help for assistance on configuring remote debugging.

All three modes display a popup saying the solution must be deployed first before it can run.

What can I do?

Are both devices in developer mode?

Yes, they are in developer mode.

Please excuse me for the bump, but I am the only one in the team where I am working on Spectator View. My internship here where I’ve been working on it ends April 27th, and I need to have Spectator View working by then. However, I am facing a setback where I think I need to work out the multiplayer networking system in order for two HoloLens headsets to communicate with each other and see the hologram in a spatial location.

The only support I have so far are the forums. Where else could I ask aside from here, the Windows Mixed Reality Developers Forum, and the Microsoft community?

I forwarded the question to Microsoft

Thanks. I apologize for the pressure; it’s business deadlines.