Are you sure that when you announced your position and your final, that it was for rw26, or was that maybe for rw08? I had this problem a long time ago (since then I only manually communicate with the ATC dialog and don’t ever use the automatic anymore, except for passenger announcements) where I know that my pilot said another runway over the radio than what was set in the EFB and where the blue boxes (which I also now have switched off) led me, so I too got a penalty for landing on the wrong runway.
Yeah this has happened several times to me too. Makes zero sense. There is no apparent reason for the runway to change and certainly not when you’re on final when all the decisions have been made. Sometimes you don’t get the final ATC interaction to say you’re on final until you’re about to touch down when you, the pilot, suddenly announce that you’re landing on a different runway - like it’s your decision. Then you get penalised for ‘undesignated landing area’.