This makes it sound like the local-connections “security” measure Apple added. Apps aren’t able to make network connections for a few seconds after launch and no one knows why. This “alert the user and retry” method is the only thing that works.
I deal with it daily in Lifeboat since my debug server is a local Pi. Every single launch the auto connect fails. Occasionally, my production instance fails the first local attempt even though it’s not automatic (app launches, window shows, I manually connect to a server).
I don’t have any better suggestions. Alert + retry is what I do.