Very odd.
C-d runs the command gnus-summary-enter-digest-group

When used on the attached article, it wipes out two http links,
turning them into a message break:

 .  1 200627||Rob Slade     :Risks for charities, non-profits, small groups
 .  1 700101||nobody        :(none)
 .  1 200626||Gabe Goldberg :AI Ethics: IP Protection for AI-generated and AI-assisted works

Gnus v5.13
GNU Emacs 26.3 (build 2, x86_64-pc-linux-gnu, GTK+ Version 3.24.20)
 of 2020-05-17, modified by Debian