No option to add a new release, only to correct/delete one.

gromit82, Thank you for your hypothesis that it might have been shown in two parts in the U.K., which I tried to track down. Searches of BBC.co.uk (too broad, can't search just the TV section, came up with the Odysseus moon lander, etc.) and ITV were fruitless, so I searched more broadly. And you're correct. I found that it was shown in 2 parts on Sky TV: https://www.sky.com/watch/title/series/10dd8467-27a3-3c74-b797-d79aa02b51f6/odysseus-returns-10dd8467-27a3-3c74-b797-d79aa02b51f6/episodes/season-1/episode-1

Perhaps somebody in authority can use this to add the 2 episodes missing from IMDb, and then correct the add release portion of the update page, and even then, use my original post to add the U.S. release date(s). 

@Hallmarkie​ Hi! Any missing episodes can be added through our online form following our help guides, and as mentioned by @gromit82 release dates have to be added/fixed from each episode.

Cheers!

@Bethanny​ Thanks, but I've already spent too much time on this, more than I should have had to given an error in the system that wouldn't have been there if whoever added the program in the first place had competed the task. It's not mine to correct. Thanks for your response anyway.