Failure to show username for contract upon join

[taoeffect]

Problem

On the testing server, there's an account (pwa2) with a group and another user that joined (username is greg) that isn't displaying:

Two problems:

1. Username isn't shown
2. Clicking user's profile icon in the user list doesn't show the ProfileCard and doesn't show any errors in the console

Solution

This is a repeatable problem. Using Troubleshooting to reset the data doesn't fix it.

1. Find out why username isn't shown and fix.
2. Find out why the ProfileCard isn't shown and why no error is shown in console either when clicked.

DM'd you credentials on GIG.

EDIT: according to @corrideat the problem is that the user had left some other group, triggering a rotation on their PEK, which means that the new group can't decrypt their username from their identity contract's attributes. So as a solution we can re-encrypt the data upon key rotation.