I’ve ensured that I’ve not got the objects set to wrap text around them.
Are you sure about that? Because the symptoms you describe certainly sound like they have! Select one of your objects and check what's selected in the Text Wrap panel.
You can set "Ignore Text Wrap" in the Text Frame options for your caption frame, but it would be better to have no text wrap except where you explicitly set it yourself.
It's possibly you selected a Text Wrap setting without any object selected, and thus you set the default for all objects. You can reset it back to 'normal' the same way.
It's a neat feature, very convenient .. except when you do something like this by accident.
With nothing selected on the page - select the black arrow tool.
Press CTRL/CMD A
Then go to Window>Text Wrap
Hit the button to have "no text wrap".
If you've set up other frames to use the text wrap - then you should reset these manually.
Thanks a lot. Cracked it first time!
Thanks. I hadn’t realised that I’d managed to set text wrap globally.