I have a Content Type defined in our tenant's Content Type Hub. This CT is based on the "Event" CT which some fields added to support it's use for a Leave Request app I'm building. There are some columns that I want to only be available/editable via PowerApps and Flow, so I made them "Hidden" in the CT. I created it yesterday afternoon, so I know it's fully syndicated by now.
In one of our Site Collections, I can view the Site Content Types and it shows up there with all of the columns that are shown in the Content Type Hub. Great! Next, I create a new ("modern") List and add that content type to it. This is where the weirdness starts. In the List Settings, I don't see any of the Hidden columns. From the Settings, if I click the CT name, no hidden columns. If I then click the Parent CT (so, the copy that exists at the site collection level), there are the hidden columns.
See this video for a more detailed description.
Thinking this was some kind of syndication issue, I went to the Content Type Hub and created a List there and added the CT to it - the same thing happens! Further thinking this may be a "modern vs classic" issue, I created a Custom List "App" and applied the CT to it - same thing. This is very frustrating. As our goal is to create a "standard" Leave Request/Approval process that can be rolled out to various departments and groups having a standard and consistent Content Type is a must. I suppose another approach is to create a site script that creates the list when/where we need it, but if we need to change something in that list, without the syndication function, we'd need to make that change in each site/list individually.
