Check box problem

I have an odd problem with some checkboxes I have in a Storyline 2 file. I have created a 'stress tool', which has pages with a column of checkboxes against a number of statements (see attached). At the end of the module you can print off an action plan based on these responses along with suggested resources.

When testing the published file in Internet Explorer I can tick all the boxes, without any problem, all works fine. However, in Chrome and Edge, I can only select the first couple of check boxes on a page and sometimes the last couple. The shadow appears when I hover over the others but they can't be ticked. I have swapped the tick boxes around and it appears the problem relates not to characteristics of the particular checkbox, but where it appears on the screen!

There are no hidden elements that could be obscuring the buttons, and I have exhausted all ways I can think of to work out what the problem might be. Has anyone experienced anything like this before?