In the velo script, I dynamically change the items in the repeater using a filter, sometimes about 4 of them and sometimes less than 5. Scrolling is ensured by the box that covers the repeater. I need it when there are few items so that the scrolling disappears and that the items are displayed correctly in the top part of the repeater.
But container or box in velo code have not propeties HEIGHT
Have you got a screenshot of what you’re experiencing?
In Wix Studio, you’ll likely want to use max-content or a similar property on the parent element to automatically adapt the height to the inner content 
In the Wix Editor, elements that are within 70px of the bottom of another element will be “dragged upwards” to reduce height.