Scrolling Wave, Naive Question, Audacity 2.1.1

Could someone please answer a probably naive question? I have made a recording but on both the recording and playback the scrolling of the visual sound wave does not occur. Both recording and playback are otherwise OK.

I get only the visual sound wave until it reaches the rightmost point of the screen, it does not scroll along at all.

Right click on the “Timeline” (the ruler at the top of the tracks panel). In the dropdown menu, select “Update display while playing”.

(The alternative method of enable / disable scrolling is to use “Edit menu > Preferences > Tracks → Update display when Recording/Playback head is unpinned”. )