DataTable:Has a fixed header, the header's border is displayed incorrectly.

[yyj961010]

Describe the bug

When the header of the datatable component is fixed, scrolling the table causes the header's border to disappear. This issue occurs consistently when the table is scrolled vertically, making it difficult to distinguish the header from the rest of the table content

Reproducer

https://stackblitz.com/edit/primevue-4-vite-issue-template-6zshgv?file=src%2FApp.vue

PrimeVue version

4.0.4

Vue version

4.x

Language

ES6

Build / Runtime

Vite

Browser(s)

Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/127.0.0.0 Safari/537.36

Steps to reproduce the behavior

Scroll the table to reproduce the problem

Expected behavior

The table header border displays normally