Rewrite rule ends up on undefined page - .htaccess

Question

This is the .htaccess of my root:
RewriteEngine on
RewriteCond %{request_filename} -f
RewriteRule ^(.*) $1 [L]
RewriteRule ^(([^/]*)+)(/([^/]{0,32})(/.+)?)?$ index.php?a=$1&q=$3 [L]
To shortener urls I used this with success:
RewriteRule ^explore/([^/]+)/?$ index.php?a=explore&filter=$1 [NC]
In this case the url https://example.com/index.php?a=explore&filter=latest%20music
become https://example.com/explore&filter=latest%20music
My problem starts here...if I shorten this url:
https://example.com/index.php?a=search&q=something
using this rule:
RewriteRule ^search/([^/]+)/?$ index.php?a=search&q=$1 [NC]
The redirection doesn't work, I end up on an undefined page.
This is my JS function for the search:
function manageResults() {
var q = $("#search").val();
liveLoad('search&q='+q.replace(' ','+'));
}
Here is my full .htaccess:
RewriteEngine on
RewriteCond %{request_filename} -f
RewriteRule ^(.*) $1 [L]
RewriteRule ^(([^/]*)+)(/([^/]{0,32})(/.+)?)?$ index.php?a=$1&q=$3 [L]
RewriteRule ^explore/([^/]+)/?$ index.php?a=explore&filter=$1 [NC]
RewriteRule ^search/([^/]+)/?$ index.php?a=search&q=$1 [NC]
RewriteRule ^welcome/([^/]+)/?$ index.php?a=welcome&filter=$1 [NC]
My function.js for the live search:
function liveSearch() {
var q = $('#search').val();
// If the query starts with #, do not execute anything
if(q == '#') {
$(".search-container").hide();
$(".search-content").remove();
return false;
}
// Check the notification state
if(typeof notificationState != 'undefined') {
showNotification('close');
}
// Search if the hashtag is typed
if(q.indexOf('#') === -1) {
var y = 'q';
var url = 'people';
$('#search').keypress(function(x){if(x.keyCode==13){q=$(this).val();if(q!=this.defaultValue){document.location='search&'+y+'='+q.replace(' ','+')}}});
} else {
var y = 'filter';
var url = 'tags';
$('#search').keypress(function(x){if(x.keyCode==13){q=$(this).val();if(q!=this.defaultValue){document.location='explore&'+y+'='+q.replace('#','')}}});
}
// If the text input is 0, remove everything instantly by setting the MS to 1
if(q == 0) {
var ms = 0;
} else {
$('.search-container').show();
$('.search-container').html('<div class="search-content"><div class="search-results"><div class="message-inner"><div class="retrieving-results">Retrieving Results</div> <div class="preloader-left preloader-dark"></div></div></div></div>');
var ms = 200;
}
// Start the delay (to prevent some useless queries)
setTimeout(function() {
if(q == $('#search').val()) {
if(q == 0) {
$(".search-container").hide();
$(".search-content").remove();
} else {
$.ajax({
type: "POST",
url: "https://example.com/requests/load_"+url+".php",
data: 'q='+q+'&start=1&live=1', // start is not used in this particular case, only needs to be set
cache: false,
success: function(html) {
$(".search-container").html(html).show();
}
});
}
}
}, ms);
}