Do you (or have you ever) had two instances of the Cisco AnyConnect VPN app configured in your org?
I just tested adding a second instance of an OIN app to my test tenant that I had already integrated with, and it originally set the display name as “Application (2)” and when I check the system logs, its alternateId is also “Application (2),” so it looks like this is to help differentiate the two instances within your logs.