This is behaviour as expected. Your called number of 55599999 matched both dial peers, but it matches dial peer 5 first because the number of digits to match are less on dial peer 5 so it matches immediate 555999 and processes the call.
You should be a little more specific in your dialplan, use differnt destinations.
Are you getting this error “Installer User Interface Mode Not Supported. The installer cannot run in this UI mode. To specify the interface mode, use the -i command-line option, followed by the UI mode identifier. The value UI mode identifiers...
The below trick might come handy when you have to add a new node to a cluster but you don't have or is unsure of the security password for the publisher. This procedure has been around for ages.
1) Login into the CLI of the Publisher.