Can't get resolution to scale properly

[NoahBK]

Hey everyone

I set up DuoStream and it works great for controller input on my upstairs 4K TV, but Moonlight is not matching the TV resolution when using DuoStream's Sunshine implementation. Streaming plays smoothly but the image is badly scaled and fairly blurry, unlike my previous Sunshine setup where Moonlight matched my monitor/TV and looked correct.

What I have tried

• Setting Moonlight to 1080p and 4K
• Restarting Duo and the TV

Other information

• Windows 11 IoT Enterprise LTSC 64-bit (10.0, Build 26100)
• Nvidia RTX 2080 Super | Driver Version: 591.86
• Using Duo v1.5.6
• Sunshine 2025.924.154138 (this version comes with Duo v1.5.6 at the time of writing this comment)
• Latest version of Moonlight through my Nvidia Shield Pro as of 3/10/26
• I have a 1080p monitor with 180Hz and my TV is a 4K HDR10 ready Onn/Roku TV that I have my Nvidia Shield Pro plugged into where I have Moonlight installed
• HDR is disabled as my monitor doesn't support it (TV does though)

Any pointers on anything else or logs or settings I should share would be appreciated. I want this to work so the kids can use the TV while I still work on my PC.

Thank you very much in advance.

[NoahBK]

Update: I don't think that Duo installed any virtual display drivers. I have uninstalled, rebooted and reinstalled and still am not seeing another display driver. I also don't have the issue of 640x480 resolution in Moonlight when I have the DuoStream service stopped through Duo Manager. If there was just a way for me to input my target resolution or know where DuoStream was getting the random virtual display from I think I could solve the issue.

[thiagorochasti]

This is a known issue with Duo's internal RDP component — it hardcodes 640x480 as the resolution passed to the RDP session, ignoring whatever resolution Moonlight negotiates. That's why the image looks blurry or badly scaled regardless of what you set in Moonlight.

Duo Manager Fix v1.0.6 includes a wrapper (DuoRdpWrapper) that intercepts this and replaces it with the correct resolution:

• Predictive: It reads your previous session's resolution from Games.log and applies it from the start
• Safe default: First connection defaults to 1920×1080 to avoid 4K rendering on the host
• Note for 4K TVs: If your Moonlight is set to 4K, connect once, disconnect, then reconnect — on the second connection the wrapper will have learned your resolution and apply it correctly

Steps:

1. Download and run DuoManagerFix-Setup.exe as admin
2. After install, connect from Moonlight — check C:\Users\Public\duordp_args.txt to confirm the resolution was intercepted correctly

You can verify it's working by seeing a line like:

=> Duo sent 640x480 (bug). Replacing with 3840x2160 [Moonlight (Games.log)]

[thiagorochasti]

This is a known bug in Duo 1.5.6 — DuoRdp.exe always receives a hardcoded 640×480 resolution regardless of what Moonlight negotiates with Apollo/Sunshine. The virtual display ends up at the wrong size, which is why the stream looks blurry/scaled.

We built a community fix for this: Duo Manager Fix v1.0.7

The installer replaces DuoRdp.exe with a wrapper that:

• Reads the exact resolution Moonlight requested from the Apollo/Sunshine debug log
• Passes the correct resolution to the real DuoRdp.exe instead of 640×480
• Updates in real-time — when you change resolution in Moonlight and reconnect, the wrapper detects it automatically and restarts the RDP session at the new resolution without needing to restart Duo Manager

For the debug log resolution detection to work, make sure Apollo/Sunshine has min_log_level = debug set in its config.

Let us know if it resolves the scaling issue or if you run into anything — happy to help.

[cbynep]

Hi, @thiagorochasti , I've had a hard time with this resolution bug for the past 2 days, only to realize that your solution works, but default shipped Sunshine configuration doesn't have min_log_level = debug set.
Reproducible on clean install of Duo 1.5.6 and latest 1.0.10 fix, min_log_level = is set to blank (no option selected).

[Black-Seraph]

I can't reproduce this issue at all.

1.5.7 receives the right resolution from all my Moonlight clients, including their SDR/HDR colorspace setting, and applies them accordingly.

If someone can reproduce this issue on 1.5.7, please get in touch via Discord to let me know so we can take a look at it together.

My Discord handle is black5eraph.