Adding BooleanIndex via ZMI results in "NotFound"

[mtrebron (Norbert)]

Update 2:

I can add an index to the zcml in my package, as in this example by @1letter

  <index
    name="customer_supplied_ean_codes"
    meta_type="BooleanIndex">
    <indexed_attr value="customer_supplied_ean_codes" />
  </index>

But "somehow" it results in a FieldIndex being added. Curious stuff..

Using this method, Plone6 adds a BooleanIndex as intended.