We have a SharePoint 2013 solution with custom content types and page layouts. Page layouts are deployed using Design Manager. The content types are inside a feature build in Visual Studio 2012.
We noticed that fields (and site columns) are disappearing from the lists (and content types). First we thought is was done (accidentally) by a user. But it's becoming more and more frequent. It's not limited to custom Site Columns. Even the basic SharePoint Site Columns like CreatedBy, ModifiedOn, etc... disappear from lists and Content Types.
Today I was noted by a user that it occurred again. All the columns where gone from a custom content type. 5 minutes later, without doing any modifications, some of the site columns were back (some not all). Seems to me like there is a job doing this.
It's currently occurring on our staging environment. Only 4 users (SharePoint developers) have access to it. I do not dare to do a db copy to production with this weird bug going on.
I do realize this is a very weird error. I have never seen anything like this in the 7 years that I build SharePoint solutions.
Anybody an idea what might cause this?