prev() method does not display spoiler text, but next() method does.

Probably your button was added before the spoiler span like this. Try changing the prepend to append then use prev(), see if it works

const $button = $("<button>Reveal Spoiler</button>");

$(".spoiler").prepend($button);

Thanks for the tip Alan. I tried both combos- append()/prev() and prepend()/next(), which both leave me with the same outcome- both spoilers are revealed when only one is clicked. I changed the 'event.target' to 'this' but same outcome. I've reviewed the code line by line in comparison with the video, and it appears identical to the video however I cannot get the clicked upon spoiler to reveal only itself, without revealing the 2nd spoiler as well. Below is my code, if anyone has a recommendation on what needs to change I'd appreciate the help.

$('.spoiler').on('click', 'button', function(event) {
  console.log(event.target);
  // Show spoiler text
  $(event.target).prev().show();
  // Hide the reveal spoiler button
  $(event.target).hide();
});  

// Create the "Reveal Spoiler" button
const $button = $('<button>Reveal Spoiler</button>');
// Append to web page
$('.spoiler').append($button);
// Hide spoiler on page load
$('.spoiler span').hide();
// When button is pressed 
$('.spoiler button').on('click', function(){
  // Show spoiler
  $('.spoiler span').show();
  // Hide the reveal spoiler button
  $('.spoiler button').hide();
});