My specs are in the attached screenshots.

Note: I had problems with Acrobat yesterday, so this morning I uninstalled/reinstalled the app via the Creative Cloud app.

1. With one or more PDFs open, choose File > Create > Combine Files into a Single PDF….

2. Add any number of files using the Add Files… command or by clicking the Add Files button.

3. Click the Combine button.

4. When the resulting PDF appears (Binder[n].pdf), focus returns to the last-selected open PDF.

In general the first thing I want to do when the combined file appears is save and rename it.

It's minor but frustrating to return to the new file, especially if there several PDFs are already open.

I combine files many times every day, so digging through a stack of windows, even with my window manager (Witch from ManyTricks), is a task I'd love to eliminate from my Acrobat workflow.

Thanks for reading and considering adding this bug to your to-do list for a future version.