Notification links to group discussions

I have just had a problem with this:
I received a number of notification emails for new comments on a discussion I started in a Group not owned by me. I have a Master Admin user.
The latest links in the emails do not work, because my username has been substituted for the group owner's username.
Actual discussion is https://pmp-art.com/library/group_discuss/608/pmp-monthly-challenge-may-2017

The first couple of Email notifications had links like
https://pmp-art.com/library/group_discuss/608/pmp-monthly-challenge-may-2017#cm1059836
which is fine.
The next few are like
https://pmp-art.com/lorna-webber/group_discuss/608/pmp-monthly-challenge-may-2017#cm1059837
and this continues up to comment #42.
Those links are not found (unless I change the username part to 'library').
Then it reverts back to
https://pmp-art.com/library/group_discuss/608/pmp-monthly-challenge-may-2017#cm1059846

I think might be because I was updating the Library's home page at approximately that time, so perhaps there was some confusion due to active user?
updated by @lornawebber: 08/06/17 12:47:18AM

Could be. The User module has some updated code in it to deal with user sessions in the beta version of jrUser ver 2.2.0b2

If it is related to active user, that should fix it. Another possibility is wrong variable if you've customized the template, check it against the current version. jrForum had a similar issue that was fixed a while back that was an incorrect link template variable.