How can I avoid infinite loop when reformatting url hash with Jquery event 'hashchange'

Issue Background

I have set up my webpage to use identifiers with prefix #s- to differentiate anchor links from other page identifiers. The window.location.hash changes to hash which moves the frame to the content in focus but also triggers the hashchange listener causing a loop.

What I've tried

I have it working for whenever the hash has changed but the only instance it does not work is when the same link it pressed (as I use this in the condition to stop the infinite loop). The code for this was:

$(window).on('hashchange', function(e) {
  if ($(location).attr('hash') != last_hash) {
    manageHash()
  }
});

What I want

I'd like to be about to find a condition or method to allow users to select a link to change the hash but also allow them to re-select the same link as many times as they want without causing a loop.

JS

last_hash = ''

function manageHash() {
  var hash = $(location).attr('hash');
  if($('#s-'+hash.substring(1)).length != 0 && '#s-'+hash.substring(1) != '#s-' ) {
    last_hash = hash
    window.location.hash = '#s-'+hash.substring(1); 
  }
}

$(window).on('hashchange', function(e) {
   if ($(location).attr('hash') != last_hash) {
      manageHash()
   }
});

$(document).ready(function() {
  manageHash()
})

HTML

<div class="contentSubSectionContainer contentSubSection" id="s-{{ subsection.slug }}">
  <h2 class="contentSubSectionFont1Bold">{{ subsection.sub_section_title }}:</h2>
  <div class="contentSubSectionContentFont1">
    {{ subsection.content_rendered|safe }}
  </div>
</div>