I believe this only happens if a Kagi search result is the first hit in the history section. If you have multiple history entries from kagi search results, the - Kagi Search
suffix gets added multiple times, so the address bar ends up looking like kagi faq - Kagi Search - Kagi Search
.
If you click the suggestion with the pointer instead of using the keyboard Orion still completes the wrong thing in the address bar, but navigates to the right page, ignoring the contents of the address bar. I guess when you press enter it's a different code path.