Since Cubase 9 in combination with Windows 10 theres no “auto line break” available in the naming below the mixer.
Before Cubase 9.5 you could use longer name sfor your tracks and they were displayed in “one line” below the mixer chanel, or “2 lines”, if they were too long.
This seem to be a Cubase/Windows10 related thing…
But to remember: It worked in Windows 10 until Cubase 9!