New page will not appear

This happened to me once, and it was a pig to figure out what was wrong. What happened was that when trying to highlight and move graphic object somewhere (using Control-click and then drag) I had accidently done a Control-Drag on the main text frame on that page. This action copied the text frame and, by shear chance, placed the new, disconnected copy directly on top of the original connected frame, in the same identical location so that the two layers of text exactly lined up and I didn't notice. I continued typing, oblivious to the fact that I was now typing in a new disconnected text frame which was overlaying the original (connected) text frame.

Maybe the same thing has happened to you. On the problem page, Control-click on the main text frame to show the handles, and then drag the text frame to move it, and see if there is another (original, connected) text frame is underneath. If not, undo the move. If so, you'll probably want to copy your latest edits from the new rogue text frame to the original text frame, then delete the new rogue text frame.

Somehow the text container on that page has become disconnected from the flow.

Try this:
Go to the Master Page. Select the text container, right click and open properties. Make sure the AutoCommect checkbox is active, and make a mental note of the Flow -- default is A.

Check each of the Master Pages that you use to make sure the flow is the same and AutoCommect is on.

Save the file if you had to make any changes.

On the body page, do Format > Page Layout > Master pages. Apply the correct master page.

That should do it....

Art