Hi @freopp! From your screenshot it looks like the Zap is setup the way that you need it to be, so you might need to do some sleuthing to find the root of the problem.

 One thing to check is the task history for the Zap. You can find the task history for all of your Zaps here: https://zapier.com/app/history/usage Or if you go to your Zaps and click on the down arrow for that Zap, you can go straight to the task history for that Zap. 

My hunch is that the Zap is being triggered twice by Slack. If this is the case then when you look at the task history you’ll likely see two tasks fire at almost exactly the same time. If you do see this, open both tasks and compare the information from the Slack trigger for both to see if there’s any different between the messages (ie are they the exact same message or is there something that differentiates them). If the information is different then you should be able to use a filter step to only allow the Zap to continue in certain circumstances (ie for one of the messages and not the other).

If you try that and aren’t able to spot the problem, the best thing to do is to get in touch with the Support Team so that they can take a closer look at the Zap with you. You can do that through the Get Help form.