text disappearing behind something on Indesign page

any help much appreciated on this -

ive got a blank space covering the lower right hand quarter of an Indesign page, where there should be text flowing.

But the text's being blocked by something, i dont know / see what.

there is no 'invisible' text wrap on a chart on lower left hand side of the page, and when i pull up a vision of all the elements on the page, i cant see anything like the outline of a box that is obstructing the text from flowing down.  any guidance on how to find the hitch v much appreciated!    David