Empty Fields after UPDATE

I have the same issue. Updated to newest version: Metabox 5.7.3 and Meta Box AUI 1.21.2 and now have a lot of empty fields in the backend on hundreds of posts. Frontend works fine.

I have this issue too using the latest version, in WYSIWYG fields. But if I click the text/html tab, the content shows up.

I am using Relationships for this post type.

Dear Support Team,

According to JC's post, it seems that this problem occurs when the "Save Field" option is disabled.
Is this an unintended condition where the option is disabled due to a bug in the update?

I manage a very large number of websites and this issue is relevant to almost all of them.

If possible, I would like to fix the "Save Field" option back to its original state so that the site can be updated properly.

I can also share the problematic sites for the benefit of developers.
I have also sent you a direct inquiry email, so please contact me if there is anything I can do to help.

Thanks & Regards,
Yumikom

Hi,

I have been able to recover many sites with the latest version of Metabox.
It's works fine now.
I set max_input_vars to 500k.

I found an explanation below.
https://support.metabox.io/topic/cannot-apply-custom-fields-to-settings-pages/

Best regardsm
Yumikom