can you please share the table code structure so that i can check the actual problem please update the complete code
for you understanding i am sharing the proper structure of html table
<!DOCTYPE html>
<html>
<head>
<style>
table {
font-family: arial, sans-serif;
border-collapse: collapse;
width: 100%;
}
td, th {
border: 1px solid #dddddd;
text-align: left;
padding: 8px;
}
tr:nth-child(even) {
background-color: #dddddd;
}
</style>
</head>
<body>
<table>
<tr>
<th><div>Company</div></th>
<th>Contact</th>
<th>Country</th>
</tr>
<tr>
<td>Alfreds Futterkiste</td>
<td>Maria Anders</td>
<td>Germany</td>
</tr>
<tr>
<td><div>Dummy</div></td>
<td>Maria Anders</td>
<td>Germany</td>
</tr>
<tr>
<td>Alfreds Futterkiste</td>
<td>Maria Anders</td>
<td>Germany</td>
</tr>
</table>
</body>
</html>
also it is happen due to this remove this css it will be fine thanks
table th {
top:0;
}