Structure Panel remove with "x" or "anchor" leaves behind empty space

when i want to display the structure panel with "Q" (left side panel is turned off) and then click the anchor and then want to remove it with "x" or the "anchor", the panel disapears, but leaves behind its space and i just can remove it by opening the preferences and turn off the left dock, which was turned off before. https://www.dropbox.com/s/2fbrxmxxp6phe7l/Bildschirmaufnahme%202023-06-23%20um%2012.41.01%20Kopie.mov?dl=0