Possible bug in Amaya 8.5: <bdo> tag

Hi:

If  I insert a <bdo> tag using the "XHTML>Character element>BiDi override"
menu and then I check the document using the W3C validator, I get the
following warning:
  required attribute "dir" not specified ".  The attribute given above is
  required for an element that you've used, but you have omitted it. For
  instance, in most HTML and XHTML document types the "type" attribute is
  required on the "script" element and the "alt" attribute is required for
  the "img" element.
but if I reload the document in Amaya, I get no warning messages

If I insert the dir attribute, the W3C validator do not find errors.

Best regards,
Barto