What you are experiencing is expected, this is what is called Inter-digit time out. What is happening is that within your dial plan there is another pattern (could be another Translation Pattern, DN or Route Pattern) starting with "0".
The following Cisco document explains this behavior:
Now going back to your concern and moving forward with the explanation, the Unified Communications Manager Platform is designed to route calls based on the closest match. When you dial "0" since there is another pattern starting also with 0 in your dial plan then, CUCM will wait for more digits. It is not until the T302 timer (that the document above mentions) expires that CUCM routes the call based on the order of the partitions set or configure on the routing device (in your scenario it is going to be the CSS of the Translation Pattern)
You will be able to check there is an over-lapping pattern within your system by going (in the Administration page for Call Manager) to Call Routing > Route Plan Report and:
1) Type 0 on the search bar and hit search and all the results starting with 0 should display.
2) Exporting your dial plan to a .csv file, open it with excel and apply filters to find the overlapping problem.
You can also reduce the T302 timer from the Call Manager service parameters from the default value (15 seconds) to a minimum of 3 seconds.
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.