Settings icon disappeared from recordings

[Ensi]

For 2 years my partner has taken a weekly music lesson via Zoom, and recorded the lesson.  After converting the video and saving it as an MP4 file, the lesson video has always included the Settings icon, which he used to slow down portions of the video for practicing.   Suddenly the Settings icon has disappeared, not only from recently recorded lesson videos, but from all the previously recorded lesson videos.   We've searched through online directions to restore the Settings icon but they are mostly either about adding the Settings icon to the computer's Start menu or for iPhones, or they just don't work.   We have an HP Pavilion x360 laptop running Windows 10.   The Settings icon is still in place on most YouTube recordings so it has not disappeared entirely, just from the Zoom-recorded videos.   How can the Settings icon be restored for the videos?