M3 MacBook Air + LG Ultrawide 100Hz: WHY AM I GETTING "NO SIGNAL"?!

Hey everyone, I'm stuck on a compatibility issue and could really use some help figuring this out.

I'm trying to run my **M-series MacBook Air** on my ultrawide, but the current setup is failing.

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### ⚠️ The Problematic Setup

| Component | Spec | Note |

| :--- | :--- | :--- |

| **Laptop** | MacBook Air M3 Chip | M-series. |

| **Monitor** | **LG 34SR60QC-B** (3440x1440 100hz) | UWQHD Native. **Has only 2 HDMI Ports**|

| **Current Hub** | **UGREEN CM478** (HDMI 1.4) | Rated for **4K 30hz** max. |

### 💔 The "No Signal" Symptom

When I try to select the monitor's native 3440x1440 resolution, the LG monitor immediately says **"No Signal"** and refuses to display anything, **even if I drop the refresh rate to 50hz or 60Hz!**

**What I know/have tried:**

1. **Lower Resolutions Work:** 2560x1080 **DO** work fine at **60Hz** on this same hub.

2. **Old Monitor Worked:** The exact same MacBook + Hub combo **ran 3440x1440 100hz perfectly** on my old **Samsung C34J79X**.

3. **BetterDisplay Failed:** Tried forcing custom resolutions and timings with BetterDisplay, but the LG still rejects the signal with "No Signal."

### 💡 The Big Question

My theory is: The old **Samsung was flexible** and allowed 100hz by compressing the color (chroma subsampling). The new **LG is strict** and is rejecting the HDMI 1.4 hub's signal outright (a timing/handshake failure), resulting in "No Signal" even at low Hz.

**The question is:**

**Will upgrading to a USB-C hub with a proper HDMI 2.0 port (rated for 4k 60hz) fix both the "No Signal" issue AND give me the full 100hz on the LG?**

I'm hoping the 18 Gbps bandwidth of HDMI 2.0 will provide the correct signal for the LG to accept the connection. Any thoughts or hub recommendations that definitely work with this resolution on M-series Macs would be awesome! Thanks! 🙏