Just add the component, make it scroll right to left, make the text string 200+ characters. It will scroll and the text will just be cut off at about 120 characters.
The text in the 'Lines' is:
{\\rtf1\\ansi\\deff0 {\\fonttbl {\\f0 Times New Roman;}}\\f0\\fs132 Motiv 17.5 Motors now available in the shop! Mod motors also available, get them before they are sold out}
Testing more, I now able to reproduce your situation. Its only happens when the line is long in pixels (due to big font size), and when WordWrap is set to False.
I've modified code to fix this issue, but, the issue can't be fixed in automatic mode. So, I've added to new properties: MaxWidth and MaxHeight, which are set to 3000 by default (as was in initial code), and used to create internal bitmap cache. So, to fit your big line in the cache, you'll need to increase MaxWidth to lets say 5000 pixels.
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The text in the 'Lines' is:
{\\rtf1\\ansi\\deff0 {\\fonttbl {\\f0 Times New Roman;}}\\f0\\fs132 Motiv 17.5 Motors now available in the shop! Mod motors also available, get them before they are sold out}