Editing command block gamertag changes to #############

I have a command block system to log which players enter and leave my realm, and to log first time players, so that I can determine who is and isn't active in the realm.

I had a player join the realm whose gamertag is thegoodbixch, when editing the testfor command block that found thegoodbixch and I edit the [testfor @a] command too [testfor thegoodbixch] all looks and seems normal, but then closing the command block editor and reopening, [testfor thegoodbixch] has changed to all ############### s and so the command block becomes useless. As a result I cannot [testfor thegoodbixch] which is a seemingly genuine gamertag!!! The attatched screenshots show this... This happens if I edit the original command block or a data picked and placed copy...