If one of your companies failed, you will need to add an "exit" Transaction (i.e. Stock Sale, Note Redemption) for $0 for each round you participated in. Seraf has an exit tool, found on the Investment page of the company's profile, to expedite the process of creating the proper "exit transactions" for you depending on which type of security you hold in a company. Learn how to record an exit in Seraf depending on the type of exit you have.
Once exited properly, the company should appear in the Exits & Returns section of your portfolio.