Copy entire chat in Messages in macOS Mojave

I'm trying to copy and paste a chat from Messages.app into an email (macOS Mojave 10.14.5, Messages 12.0 (5500)). When I go into Messages and select all using command+A, the entire conversation is highlighted as if it's all selected. However, when I then copy and paste, only the very first selected message gets pasted. I tried selecting manually with the mouse, using Edit > Select All, and doing all of the above with the message opened in a separate window, but none of those changed the result.

I came up with one kludgey solution of making a PDF to share by selecting File > Print… and then PDF > Save as PDF. That creates a PDF that can be shared but copying and pasting from it remains a mess.

If I'm not mistaken, this was possible in earlier versions of macOS (I seem to even remember the formatting pasting quite nicely).

So how do you copy the entire chat in Messages?

Solution 1:

Scroll up before copying.

I just observed it. Copy-pasted in textedit and used a service to count words which increased every time I scrolled up. Also scrolling up can be sluggish at times due to media, previews etc., so it might be rendering it from another format the source of which I presume is /Users/me/Library/Messages/Archive/01-03-2019/My Friend on 01-03-2019 at 01.11.05.ichat