We have crosses on each panel which closes panel. Tap on panel icons in top right corner also closes panel. It's good when panel is undocked. But quite often when some of panels are already opened and docked to screen, I accidentaly by habit tap on panel icon in top right corner and it closes. After that you need to open it and move it to dock it back.
Would be good to check: if panel is docked on screen, then do nothing by icon tapping. So, we can close docked panels only with crosses on panels. This will improve user experience.
Thanks