Hi there! I see you're having trouble getting the speed test to load and run in the TP-Link Tether app on your iPhone. I'd be happy to help you figure this out.

Before we dive into solutions, could you share a bit more info? For example:
- Are you connected to your TP-Link router's Wi-Fi network when trying the speed test?
- Have you tried restarting the app or your router yet?
- Is your router's firmware up to date?
- Are you using any VPNs or proxies on your iPhone while running the speed test?

Knowing these details will help me tailor the best steps for you. Meanwhile, here are some straightforward things you can try:

1. Ensure you are connected to your TP-Link router’s Wi-Fi. The speed test feature works best when your device is on the same network as the router.

2. Restart the Tether app. Fully close it on your iPhone and reopen it to clear any temporary app glitches.

3. Restart your router. Power it off for about 30 seconds and power it back on. This often resolves network hiccups.

4. Check for firmware updates. Open the Tether app, navigate to your router’s settings, and see if there’s a firmware update available. Updating can fix known issues including speed test glitches.

5. Disable any VPNs or proxies on your iPhone. These can interfere with the connection needed for the speed test to function properly.

If these steps don’t get the speed test running, we can consider more specific troubleshooting such as testing speeds through the router’s web interface or checking for broader network issues. Let me know how it goes, and if you've already done any of these steps!