Edit the settings for the library in which this series lives. Disable the setting “Prefer local metadata,” if it is enabled. Then, Plex Dance the series again.
Failing that, check to see if that episode is being picked up as a duplicate of another. In the Library tab of the library in question, change the view to episodes. Then, apply the Duplicates filter:
If anything shows up with this filter, hover over its poster, select the vertical ellipsis, and then select Get Info. It will show the files associated with the item.
Finally, it’s generally a good idea to include the series release year in at least the series’ folder name. This helps disambiguate series for which there are multiple candidates for a match. In this case the folder containing this series should be named “Ultraviolet (1998)”.
