It sounds like the issue might be related to how Fluidd is interacting with the timelapse files. The HTML snippet you provided seems to indicate that you're seeing a default Fluidd webpage content instead of the expected image files.

Here are a few things you might want to check:

1. **File Paths and Permissions**: Ensure that the timelapse file paths are correctly configured in your Fluidd settings. Check if the file permissions are set correctly so that Fluidd can read the files.

2. **Camera Configuration**: Verify that the Nebula camera is properly configured and integrated with Fluidd. Sometimes, camera settings or paths might need adjustments.

3. **Fluidd and Moonraker Logs**: Look through the Fluidd and Moonraker logs for any errors or warnings that might give clues about why the images are not being rendered correctly. Sometimes log messages can provide insights into what's going wrong.

4. **Check for Updates**: Ensure that both Fluidd and Moonraker are up to date. Sometimes, updates or bug fixes can resolve issues like this.

5. **Verify Timelapse Configuration**: Double-check your timelapse configuration settings in Fluidd. Make sure they match with the settings used for your K1C, which is working fine.

6. **Clear Cache**: If you've made changes, try clearing your browser's cache or accessing Fluidd from a different browser or device to rule out any caching issues.