Hi,
Unfortunately, we can't do anything about that. Chosen is a dropdown styling library included in Joomla. HikaShop is just using it when you activate it.
It's because:
- Your template doesn't have enough width available on the position where you put your filter module
- The width of dropdowns created with chosen is fixed in the chosen CSS
- You've turned on the "use chosen library" of the HikaShop configuration, or your template adds chosen to the page
Either turn off that setting, or fix the CSS of chosen, or increase the width available in that position of your template.