Fields become empty.

Yep. Through the database, it works fine. Not sure why it was not from the admin panel, through the custom fields.

Field popups__add was not in database at all.

Do you have any ideas about why it may happen? Plugin? Virus? Credentials vulnerability? Other stuff?

But what did you do for the sections__add to fix it? Is there a wrong format too?

I mean, I see that the other pages, like "about-us" or "policy", are missing their meta boxes as well. And I see them in custom fields. The same situation.

But I am not sure how to debug it, when we have big strings and it is not obvious.
I found several unserialize services which can unserialize string. Some of them throw errors some of them not and return an array. I do not see anything suspicious here (about us page)

a:4:{i:0;a:4:{s:12:"section-name";s:29:"Intelligent testing solutions";s:18:"sections__template";s:8:"overview";s:8:"overview";a:2:{s:15:"overview__title";s:29:"Intelligent testing solutions";s:19:"overview__sub-title";s:157:"We work to provide the digital economy with automated testing solutions that are affordable, simple, and comprehensive to meet a variety of automation needs.";}s:8:"contacts";a:1:{s:15:"contacts__items";a:1:{i:0;a:1:{s:14:"contacts__type";s:5:"email";}}}}i:1;a:4:{s:12:"section-name";s:11:"Our mission";s:18:"sections__template";s:8:"features";s:8:"features";a:1:{s:18:"features__articles";a:2:{i:0;a:4:{s:5:"title";s:11:"Our mission";s:4:"text";s:149:"We have seen our clients face the frustration of finding an automation solution that is affordable, comprehensive, easy to set up, and simple to use.";s:5:"image";s:2:"47";s:18:"features__articles";a:1:{i:0;a:2:{s:21:"title_icon_visibility";s:4:"text";s:4:"text";s:387:"To tackle these problems, we initially developed intelliQ Studio as a free alternative to commercial test automation solutions, and as a versatile tool that is easy to use for both beginning and advanced testers.

Since then, intelliQ Studio's adoption rate has accelerated. The tool was ranked as a top automation tool by popular automation websites and by many testing communities.
";}}}i:1;a:4:{s:5:"title";s:9:"Our story";s:4:"text";s:151:"We have seen our clients face the frustration of finding an automation solution that is affordable, comprehensive, easy to set up, and simple to use.
";s:5:"image";s:2:"46";s:18:"features__articles";a:1:{i:0;a:2:{s:21:"title_icon_visibility";s:4:"text";s:4:"text";s:385:"To tackle these problems, we initially developed Katalon Studio as a free alternative to commercial test automation solutions, and as a versatile tool that is easy to use for both beginning and advanced testers.

Since then, Katalon Studio's adoption rate has accelerated. The tool was ranked as a top automation tool by popular automation websites and by many testing communities.
";}}}}}s:8:"contacts";a:1:{s:15:"contacts__items";a:1:{i:0;a:1:{s:14:"contacts__type";s:5:"email";}}}}i:2;a:4:{s:12:"section-name";s:8:"Contacts";s:18:"sections__template";s:8:"contacts";s:8:"features";a:1:{s:18:"features__articles";a:1:{i:0;a:1:{s:5:"image";s:2:"47";}}}s:8:"contacts";a:4:{s:15:"contacts__title";s:10:"Questions?";s:20:"contacts__title-text";s:71:"Have a question for the team about our products or our services? Shoot!";s:25:"contacts__additional-info";s:52:"Organization number: 87163457836, Stockholm, Sweden.";s:15:"contacts__items";a:2:{i:0;a:3:{s:4:"icon";s:2:"21";s:14:"contacts__type";s:5:"email";s:17:"contacts__contact";s:16:"[email protected]";}i:1;a:3:{s:4:"icon";s:2:"21";s:14:"contacts__type";s:5:"phone";s:17:"contacts__contact";s:14:"+46 73430 5337";}}}}i:3;a:5:{s:12:"section-name";s:36:"The future of test automation is now";s:18:"sections__template";s:4:"hero";s:4:"hero";a:2:{s:11:"hero__title";s:36:"The future of test automation is now";s:13:"hero__buttons";a:1:{i:0;a:3:{s:11:"button_text";s:14:"Request a Demo";s:15:"button_behavior";s:9:"open_page";s:11:"button-link";s:31:"http://intelliq.se/#get-started";}}}s:8:"features";a:1:{s:18:"features__articles";a:1:{i:0;a:1:{s:5:"image";s:2:"47";}}}s:8:"contacts";a:1:{s:15:"contacts__items";a:1:{i:0;a:1:{s:14:"contacts__type";s:5:"email";}}}}}