My experience with reports in Pro is extremely buggy. I tried using them once and regretted it, will not be using them again and told everyone in my org to do the same. On my first try at exporting, my report that only was supposed to produce about 50 pages started 'generating' hundreds and I had to force quit the app. I sent a laundry list of the bugs I encountered to a product engineer, who was able to reproduce about half of them. We'll see if it improves.
