Select the text frame.
In the context menu -- text frame options…
Check ignore text wrap.
BEst to do with a specific object style
Actually, it would be better to turn off the text wrap on the image frame unless you need other text to wrap around it.
It sounds like you might have text wrap enabled as a default, which you can fix for new objects by opening the Text Wrap panel and selecting the No Text Wrap button with no object selected. Do that with no files open as well to be sure it is not set as the default in new documents.