Cannot place calling card in Silver Shroud quest

It sounds like you're bugged. You could reload to an earlier save and have another go but since you're fine with console commands...

I don't know the quest ID for the quest you're on so what you'd need to do is open the console by pressing ~ or ' and then type sqt to generate a list of all current quest targets, this should reveal to you the quest ID for the bugged quest. Then you can do completequest <QuestID>, which will complete that quest.

From my experience, the quest doesn't acknowledge the calling card placement if you place it BEFORE you are prompted to actually do so (i.e placing the calling card as soon as you kill the target, before leaving enough time for the quest to update).

(This happened to me as well, but luckily I had saved just prior and I reloaded a few times to see WHY it had happened.)

Also it isn't limited to Kendra, this happened to me with AJ (the drug dealer)

While this doesn't help in fixing the issue, it should help in avoiding it, just make sure to always quicksave right before each target and you shouldn't have any problems.