Hello @Mvatan,
@retention and @Paul S, actually has some great flow troubleshooting tips in a similar Community post below that I would recommend reviewing:
On top of those troubleshooting tips and areas to check, I noticed that Smart Sending is enabled on your email from your screenshot - the mail with the check mark icon. I would recommend double checking to see if the email you tested was actually queued up for the flow but was actually skipped due to Smart Sending. You can check this by clicking on Email #1 > “View all Analytics” from the left side of the interface > Recipient Activity > “Skipped” to see all the contacts who were skipped and their skipped reasons. If this was the reason, your email was skipped and didn’t receive the email, the Guide to Smart Sending in Klaviyo guide can offer insight into how to disable this feature.
Hope this helps!
-David