There are two different "Refresh" links on the main Gedcompare page.
I can’t commiserate with that one, but I can offer some empathy. I’ve uploaded quite a few GEDCOMs and have always wanted to go ahead and get them knocked out, just to find out I needed to wait until the report was ready at some inordinate point in the future.
Thanks for the warning, though! I’ll try to learn from your mistake, rather than doing the same