Problems with tabs

[Zuzz]

Some day ago I upgrade espocrm to the latest version and add tabs to panels.
Old details form html screenshot in attach.
Function uses
this.$el.find('.middle > .panel[data-tab]').addClass('tab-hidden');
to hide and show panels. So marked panels might be one level to top.
So tags doesn't work for them, but work for new-created Entities.

[Zuzz]

I've found the reason.
We use custom field with template, it contatins nested <div> with complex classes.
We check correctness with online html Validation Service and by eyes, it seems to be correct.
But when remove this field from form everything works fine.