When using the backspace key on the namespace "pills", the UI element's default behaviour is to convert the pill content (namespace name) into a string and remove characters one by one (to facilitate using this string for autocomplete).
In our case, not their label (e.g. "Article") is shown (and reduced to "Articl", "Artic", ... as expected), but their id (because we use this as their data attribute).

Expected behaviour:
When using backspace key on the namespace "pills", the pill content (namespace name) is converted into a string, can be remove character by character, and hence used for autocomplete