I managed to resolve the issue.

In my case, the problem was caused by a plugin that automatically updated Livewire to version 3.5.16. This update introduced the issue with the modal backdrop.

To fix it, I forced Livewire to revert to version 3.5.12 by editing my composer.json file and "livewire/livewire": "3.5.12"

Then, I ran the following command to apply the change: composer update livewire/livewire

After downgrading Livewire, the issue was resolved, and everything works as expected again.