Why is data not being sent from one field in the form?

Question

Django

At some point, data from one single field in the richtextfield (CKEditor) form stopped being sent on the non-development server and on the production server, everything is fine with the rest of the fields, when creating a new record, nothing is entered in the field, when changing an existing record, the field does not does not respond to changes. Everything works through the admin. What can be wrong?
* Mezzanine 4.3.0
* Django 1.11.14
* Python 3.6.0