Hi Jorn,
Sorry for the late reply.
Normally, both text elements (basic and rich text) should fill out the container depending on the amount of text.
I’m guessing now: you use the rich text element and have
tags that cause line breaks in your text. On the rich text element, click “Text” in the upper-right corner and see if you can find
tags.
If so, remove them. If not, a live link would be very helpful.
Best regards,
timmse