How do you merge pdfs without creating a pdf portfolio?

I'm using Acrobat Pro DC and when I go to merge two PDFs, I do Tools > Combine Files > select my PDFs that I want to merge, and then somehow it creates a PDF portfolio, which I don't want. I think this changed with the last update, but how do I get it to merge my files without creating a portfolio? I'm not selecting "Create a PDF Portfolio" anywhere, and I used to be able to do this before the update. Any ideas?