Dear @Micol,
Upon reviewing the issue you reported regarding the Header builder, we have conducted tests using both the non-XStore theme and the default WP theme. We have observed that the problem persists under both conditions. This indicates that the issue may not be directly related to our theme but could potentially be linked to the server configuration or the plugins currently active on your website.
Additionally, we encountered a similar error while attempting to edit the Footer and other templates. During our troubleshooting efforts in Elementor Debug mode (https://prnt.sc/4pm82a3QUDQb), we were unexpectedly redirected to a maintenance page (https://prnt.sc/LZQisatFEkrk), which, according to our records, you mentioned was disabled. Could you please confirm this?
Given that the issue also occurs with the default Twenty Twenty-Four theme, we recommend contacting your hosting provider as the problem could be related to server configuration.
Thank you for your attention to this matter. We look forward to your confirmation regarding the maintenance page and any further assistance you might require.
Best Regards,
The 8Theme Team