I have tried to change the Signature Decay method but it still seems broken as it does not allow me to save. This is the same situation as several months ago. Is there a secret spidey way to make this work perhaps?
After hitting save, the signature decay method is saved. The decay method only applies to new activities moving forward, it does not recalculate the progression with the changed decay method. HTH
If you would like, you can “force” it to update older activities by going to your last breakthrough and deleting/reuploading it. All activities since that activity will then be recalculated using the new signature decay method. Cheers