My only thought is that the clue and entry for ENDED don't seem to match in terms of parts of speech? Like the entry is a verb and clue is looking for a noun, if I'm thinking of this properly?
I'm glad you enjoyed it! I can see what you mean about 5D. I wanted to make some allusion to OMEGA being the end, as opposed to ALPHA being the beginning. It was awkwardly worded, all the same.