If an "If/Else" action is not working, you likely have two campaigns with the same name in your account. The "Send Email" action could be referring to one campaign, and the "If/Else" action could be referring to the other campaign.
To fix the issue, you'll need to change the name of the campaign in the "Send Email" action of your automation. Then, update the corresponding “If/Else” statement to match.
Note that the same issue can occur if you use any email-related automation triggers ("Opens/Reads" trigger, "Clicks a link in an email" trigger, etc).
For other common issues related to automation check the "Top Automation Issues" help article.