PHP Pagination page links showing no results after page 1 - php

Question

I've set up a search of my database with pages. There are two searches performed on this page, one for users and one for pets, but for now I am trying to get it to work with the pet search only. The search itself functions, and the results display properly for page 1 with the appropriate amount of linked pages after. My problem comes in when I try to go beyond the first page. I have checked the search itself and it brings up results in my database, but clicking the page link results in a 'No results' message. Here is my initial setup:
<?php
if (!isset ($_GET['page']) ) {
$page = 1;
} else {
$page = $_GET['page'];
}
$results_per_page = 10;
$page_first_result = ($page-1) * $results_per_page;
$num_results = 0;
include("includes/header.php"); // This is where the first search is performed to check for number of rows
if (!empty($pet_search_result)) {
$number_of_result = mysqli_num_rows($pet_search_result);
$num_results = mysqli_num_rows($pet_search_result);
}
else if (!empty($user_search_result)) {
$number_of_result = mysqli_num_rows($user_search_result);
}
else {
$number_of_result = 0;
}
$number_of_page = ceil ($num_results / $results_per_page);
?>
This is of course followed by the search where users enter parameters. This search works perfectly without pagination. After those have been entered, the code says this:
$queryConditions = $queryConditions . ' LIMIT ' . $results_per_page . ' OFFSET ' . $page_first_result;
$pet_search_result2 = mysqli_query($con, "SELECT * from pets WHERE $queryConditions");
Results are then displayed, and here is where the problem hits.
for($page = 1; $page<= $number_of_page; $page++) {
echo " <a style ='color: white;' href='?page=$page'> $page </a> | ";
}
Clicking the link to page 2 or any other page leaves the user on the search page with no results shown. I have checked and the proper page number is picked up on page 2, the offset is correct, and the search itself turns up the appropriate results when performed directly in the database.
I have tried using
htmlentities($_SERVER['PHP_SELF'])
and
$_SERVER['PHP_SELF']
so that it read:
echo " <a href='" . htmlentities($_SERVER['PHP_SELF']) . "?page=$page'> $page </a> | ";
or
echo " <a style ='color: white;' href='" . $_SERVER['PHP_SELF'] . "?page=$page'> $page </a> | ";
as the redirect url, and none of these worked. I was expecting clicking page 2 to show me the search page with the second set of 10 results. Instead it acts as if no search has been performed.