When someone joins a group via a group link, the message shown in the app is "X added X." as opposed to the Android version's "X joined the group via the group link."
Actual Result:
A message is shown saying "X added X."
Expected Result:
A message should be shown saying "X joined the group via the group link."

Signal Version:
v1.39.4
Operating System:
Windows 10 64-bit
Linked Device Version:
Android 5.0.10
Thanks for reporting. This should be fixed in an upcoming release.
Is this open for contribution? I'd like to give it a shot.
I've been able to replicate this by creating an invite on Android version 5.1.8, then sending the invite and having the Desktop version 1.39.5 installed, On mobile, it shows up as intended, however on Windows desktop the bug shown above is observed.
@flozender No, it's not open for contribution. It's part of a comprehensive new set of GroupV2 Link strings and functionality.