Sounds like you need to configure the string ports via the web interface, or upload the configuration from xlights. By default, the controller is set up only to run 50 pixels per port unless you adjust that.
https://docs.google.com/document/d/1CZ1rDMsKNkaTfZemvHUTL8JH9NVjtndyzC0qlMYAOz4/edit?usp=sharing