1) Which browser, operating system and versions of those are you using?
Using Chrome browser on ChromeOS, both version 97.0.4692.70
2) Which version of Memex are you running?
Memex browser extension for Chrome.
3) What are the steps you took that lead to the bug?
Imported Chrome bookmarks where two folders with identical names in the same parent folder existed (allowed by Chrome, but an accidental state).
Problem
When importing bookmarks from Chrome, which allows folders with identical names in the same parent folder, two identically named spaces were created. When trying to manually move the single item in one of the two spaces to the other identically named space that contained many items, the space editor would unassign the space when selecting the second space with the same name. Unassigning all spaces, and then selecting the one to assign it to added both identically named spaces, and clicking the X to remove either removed both instead.
Fearing the effects if one of the two space names was removed, I instead renamed one of them to avoid duplication. I was then able to properly move the single item into the other space and then remove the old space.