My pet peeve are mobile apps that work with good connectivity (mobile or wifi), and also work with no connectivity at all, but when there is patchy connectivity

My pet peeve are mobile apps that work with good connectivity (mobile or wifi), and also work with no connectivity at all, but when there is patchy connectivity take a minute or so to decide which mode to work in. Spotify I'm looking at you. Especially on screens that absolutely should not need to request data from the server to render information.