I would wait one month. Depending on the size of the negative I will either ask them to wipe it out, but if they don’t then I’d consider going an additional month or so until the next portal update then remove them from my sites if the player does not return to play more.
I’ve been lucky to not have very many negatives over the past few years, but I have had one or two programs with negative-carry over wipe out a loss for me.
I think it just depends on the situation.