It is a "feature" of other completion tools that differentiate between the selected candidate (usually the highlighted one) and the current input (which may be incomplete, and usually not what you want to select, but sometimes is (e.g. when you want an empty string, or to choose something that is not a candidate but similar to one e.g. with fuzzy matching)). That happens with helm and ivy, probably selectrum, and other backends that try to improve on the vanilla completing-read interface.
John
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Professor John Kitchin (he/him/his)
Doherty Hall A207F
Department of Chemical Engineering
Carnegie Mellon University
Pittsburgh, PA 15213
412-268-7803