Could this be what you meant to achieve...? And by the way, the opening Paragraph Tag:< p > could contribute to some unexpected &/or sluggish behaviour since it was just opened without being closed anywhere in your code... I commented it out... You may try to see if it helps....
<?php
// CREATE A STRING VARIABLE TO HOLD THE ENTIRE OUTPUT TILL YOU ARE READY TO RENDER IT TO THE STREAM...
$strOutput = "";
while($row = $result->fetch_assoc()){
$Tchannel = $row['chan'];
$strOutput .= '<img src="https://static-cdn.jtvnw.net/previews-ttv/live_user_' . $Tchannel . '-320x180.jpg" alt="Thumbnail"><br />';
// WHY DO YOU NEED THIS OPENING PARAGRAPH TAG? WHERE IS IT CLOSED IN YOUR CODE?
//echo '<p>';
}
// RENDER THE OUTPUT
echo $strOutput;
?
If you need the images wrapped in paragraph tags, you can do it differently:
<?php
// CREATE A STRING VARIABLE TO HOLD THE ENTIRE OUTPUT TILL YOU ARE READY TO RENDER IT TO THE STREAM...
$strOutput = "";
while($row = $result->fetch_assoc()){
$Tchannel = $row['chan'];
$strOutput .= '<p>'; // <== OPEN A PARAGRAPH
$strOutput .= '<img src="https://static-cdn.jtvnw.net/previews-ttv/live_user_' . $Tchannel . '-320x180.jpg" alt="Thumbnail"><br />';
$strOutput .= '</p>'; // <== CLOSE THE PARAGRAPH
// OR ALL IN ONE LINE:
// $strOutput .= '<p><img src="https://static-cdn.jtvnw.net/previews-ttv/live_user_' . $Tchannel . '-320x180.jpg" alt="Thumbnail"><br /></p>';
}
// RENDER THE OUTPUT
echo $strOutput;
?>