I have the same problem. I use Foxit Reader which can copy text and retain formatting
I actually saw it with Foxit works but still not with Acrobat.
What a pity!
I find it ironic after all these years, from the time Adobe created the reader and Adobe are the folks who created pdf, the copy text doesn't work properly. Not that only, Foxit had the copy text feature loooong before Adobe!
Yes it's true.
Moreover, Adobe Reader is affected by numerous faults and they are updated only every 3 months. It's not very serious.
But I told them this problem reported in bug report, but still no changes since version 9.2.0.