If the table is not wide enough there isn't enough room for the entire filter UI and the left part gets cut off including the close X. The only way to remove the filter is to refresh the page.
Seems like the filter UI should flow like most everything else.
Edit:
The above effect happens if the table is on the right side of the page. If there is enough room to the right of the table, the filter UI will overlap the adjacent component like this:
