I have some "text" type custom fields. After I update a post on which these fields are appearing all are getting appended a https:// inside the field. (even if they are not urls)
For example if I have a "name_field" and add John, after I save it, it will be http://John. (and can't remove it afterwards from the interface)
Do you use any custom code to sanitize the field and add "http" to the field value after saving? Please share the code that you use to create the field group or export the field group to a JSON file and share it here. I will help you check the field settings.
Following the documentation https://docs.metabox.io/extensions/meta-box-builder/#export--import