Fill array in PHP using Mysql - php

Question

I'm developing an android application that uses PHP and makes requests with Mysql. Initially I tested all the features on the local server to then migrate it to an online server, in this case, Hostinger.
One of my PHP files returns the value of an array correctly on the local server, however, when using the same PHP file on the online server with the same database, the array only responds to TRUE when I run echo.
I tried doing the echo of each line and it is working perfectly, just not being able to associate the values with the keys in the array.
$result= mysqli_query($connect, $sql);
while ($patients= $result->fetch_assoc()){
echo $patients['group']; //prints OK
echo $patients['exercise_name']; //prints OK
echo $patients['use_exercise']; //prints OK
$insert[] = array("group" => $patients['group'],
"name" => $patients['exercise_name'],
"use" => $pacientes['use_exercise']
);
}
echo json_encode($insert); //prints TRUE

Answer 1

My mysql output from $result:
+------------------------------------------+
| group exercise_name use_exercise |
+------------------------------------------+
| Knee Knee _1 1 |
| Knee Knee _2 1 |
| Knee Knee _3 0 |
| Knee Knee _4 0 |
| Knee Knee _5 0 |
| Shoulder Shoulder_1 1 |
| Shoulder Shoulder_2 0 |
| Shoulder Shoulder_3 0 |
| Shoulder Shoulder_4 0 |
| Shoulder Shoulder_5 0 |
| Ankle Ankle _1 1 |
| Ankle Ankle _2 0 |
| Ankle Ankle _3 0 |
+------------------------------------------+
The rest of the PHP code is really not relevant to this. I ended up getting this result from it. My only problem is passing everything to the array. I've tested with another PHP file and it printed how it was supposed to, so I don't know what is happening.