Hello, I made this menu using the same elements as you did in the demo (Extra Menu list), but the text breaks into two parts (Watercolour Brushes, Waterbrush, Varnishing).
I have visited your website. It seems that you are using four columns in the HTML Block but the nav link texts are greater than the width of the column in which they are added that’s why they are displayed like that.
Please try to set the columns to three and clear cache and check back.
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