I suppose it happens due to Line Print mode selected as a printer language. In this mode it will treat all CPCL commands as a printable text. To use CPCL you need to configure your printer to use ZPL language with following command:
! U1 setvar "device.languages" "ZPL"
This way your printer will be configured for both languages, ZPL and CPCL. See here for details please: How to Enable ZPL or Line Print Mode on Mobile Printers
In case you still need to use line print mode for some reason then there are some commands that make it possible to format your line print mode printings with advance features:
Software Engineer, Kutir Mobility
Posted on behalf of Zebra Technologies