These oscillator indicators with "overbought" and "oversold" zones need to be used very carefully, if at all.
"Overbought" and "oversold" may not really exist at all.
People who write "trading teaching materials" have a different idea about them from the idea that prices and markets have.
The best analogy I've seen is the one comparing "speed" and "acceleration" of a car.
If the car gets faster and faster, you know it can't continue for ever, so that's like "overbought". Some time it will come down. It can't accelerate for ever. But who knows when?
It can be "overbought," and the rate at which it accelerates can very gradually slow down, but meanwhile it's still going very fast and maybe even still gaining (a little) more speed for a long time.
The time to enter the "short trade" might be when you see the driver put the brakes on. When it comes back from above to below its "overbought" level. Not before?
Or maybe just trade price and not indicators, as Tommor suggests?