I reported this issue to ExpertFlyer yesterday and they are working on a fix with their data supplier. They suggest as a temporary workaround to do the search by specifying BA as the only airline in the search, in other words do not include any other airline (or select oneworld alliance) in the search criteria and do not select the 'Exclude Codeshares'.

Some searches work using this method. I have noticed saved queries do not appear to work using the workaround.