[Pharo-project] obsolete behaviors in image

Hi In 20547, I do: SystemNavigation default obsoleteBehaviors. and obtain: an Array(Behavior Behavior class) Which sounds weird. I tried with: SystemNavigation default obsoleteBehaviors first == Behavior and it's false. So at least it's not the class installed in system dictionary, but an older version (probably). I tried to remove them with: SmalltalkImage current fixObsoleteReferences. 3 timesRepeat: [ Smalltalk garbageCollect ]. but no changes. Is this a known issue? I used #pointersTo to see who is pointing it but I didn't understand yet. Martin