I think I have found a bug.
In greek morph searching on UBS4 I did a lemma search first for dikaios, and then looked for the root dik using the wild card dik* - I got the same results as for dikaios.
I opened a new panel and searched for the lemma dikiaosyne, then again tried to look for the root dik using wildcard. Now got the same list as dikaiosyne. But the visible syntax was exactly the same as the first dik* search.
I looked in the history in the second panel and searched on the previous dik* search and got the previous result (i.e. the list for dikaios). So it is not panel dependent.
Any ideas?