Fixes:
● Disappearing arrow buttons from horizontal scroll lists in channels
● The popup stayed open

Links:
● Firefox
   https://addons.mozilla.org/firefox/addon/multiselect-for-youtube
● Google Chrome
   https://chrome.google.com/webstore/detail/gpgbiinpmelaihndlegbgfkmnpofgfei
● Microsoft Edge
https://microsoftedge.microsoft.com/addons/detail/fkabkbedpefhdbkmgmfineacfpoghnno