[BUG] Modal opening causes page to 'pop' down, cut text, and become unscrollable

[xannyxs]

Describe the bug When opening a modal (e.g., the share button modal), the page unexpectedly "pops" down, causing part of the text to be cut off. This action also makes the entire page unscrollable, significantly impacting user experience and functionality.

To Reproduce Steps to reproduce the behavior:

1. Navigate to "manage livestream page"
2. Click on the button to open the modal (e.g., the share button)
3. Observe the page suddenly moving down
4. Notice that some text is now cut off
5. Attempt to scroll the page

Expected behavior When opening a modal:

1. The page should remain in its current scroll position
2. No text should be cut off or obscured
3. The background page should either remain scrollable or be properly locked without shifting content

Screenshots

https://github.com/user-attachments/assets/d565cca4-dd91-4aa0-bb9a-300a6de2916c