Why does the iframe disappear?

Question

css

Link: _ jum.ee/gazovye-raboty
There is an iframe on the page

<iframe src="http://adlab.ee/projects/7jum/kataloog.pdf"></iframe>

1) Why does this iframe stop loading the specified .pdf file when turning on the Google Chrome console and reloading the page?

2) Is there something wrong with the CSS of this iframe that might cause it not to open to full width on some devices? A friend complained that the iframe is displayed in a small window on the left..