Duplicate users appearing in groups after upgrade to 9.4

Hi tmortagne,

We've recently upgraded to 9.4 and I've started getting reports of duplicate users appearing in some of our groups in XWiki. When I hover over the names of the users when viewing the group membership the duplicate users have the same names, i.e. they don't have a 1 on the end. Since this has started happening the affected users are losing access to the pages that the groups have permissions set against.

Any ideas?

Thanks,

Ben