For some reason when I attempt to enable the built-in plug-in Time Scale, it shows as enabled before I click OK but stays disabled after. Might I try a reinstall?
There isn’t a built in effect called “Time Scale”.
There used to be a built in effect called “Sliding Time Scale / Pitch Shift”. “Sliding Time Scale / Pitch Shift” has now been renamed “Sliding Stretch”.
Have a look to see if “Sliding Stretch” is in your Effect menu - if it is, then you don’t need to do anything - the “Time Scale” entry is probably just a left-over from a previous version.
The current version of Audacity is 2.3.1, and it is available via the Audacity website: https://www.audacityteam.org/download/windows/
This worked for me, thank you!