Querying MySQL database retrieves invalid results

Question

I am querying mysql database to return jobs from one table and the job meta data from another table. I have a form with two inputs, one is title and second is location so a user can query w.r.t title or location or both. When I type in title input and leave the location one blank then I retrieve results, efficiently, but when I type in the latter input as well, only the same results are retrieved again with no change. When I empty the former input, then I receive unexpected results. Total jobs in the table are 460+ and the results I retrieve are in thousands and when I check the json object received, all of the data is repeated after 460+, and then from start to end and so on. I don't know what's the problem.

My basic need is to query the database and get results w.r.t both inputs, or even when they are empty.

The Form

<form action="" id="search_form">
   <input type="text"  class="job-search-inp job-title-inp" autocomplete="off" name="job_title" placeholder="Job Title, Company name">
   <input type="text"  class="job-search-inp job-type-inp" autocomplete="off" name="job_loc" placeholder="City or Country . . . ">
   <button  type="submit" id="submit_btn"> <i class="fas fa-search"></i> </button>
</form>

Client Side

var searchForm = document.querySelector("#search_form");
searchForm.addEventListener("submit", function(e) {
  e.preventDefault();
  var json = new Globals().toJSONString(this);
  fetch("/fetch_jobs", {
    method: "POST",
    headers: {
      "Content-Type": "application/json"
    },
    body: json
  }).then(function(t) {
    t.text().then(function(res) {
      console.log(JSON.parse(res));
      populateJobs(JSON.parse(res));
    })
  })
})

Server Side Scripts with Query

app.post("/fetch_jobs", function(req, res) {
  new AccessAPI(req.body, res).retData();
})

function AccessAPI(data, response) {

  this.retData = function() {
    console.log(data['job_title'], data['job_loc']);

    ms_connect.query("
SELECT `companies_jobs`.*
     , `companies`.`name`
     , `companies`.`location`
     , `companies`.`image` 
  FROM `companies`
     , `companies_jobs` 
 WHERE `companies_jobs`.`comp_fk` = `companies`.`id` 
   AND CONVERT(`companies_jobs`.`job_title` USING utf8) LIKE '%" + data['job_title'] + "%' 
    OR CONVERT(`companies_jobs`.`job_loc` USING utf8) LIKE '" + data['job_title'] + "%' "
, function(err, rows) {
      if (err) {
        throw err;
      } else {
        response.send(rows);
      }
    })
  }
}