Automatic Avatar using LDAP doesn't provice correct name initials in some cases

Description:

Using LDAP Connection to an ActiveDirectory.
It's working fine for nearly all users, except for some:

In these cases, it should be GS and ES.

In my case the "Use full name initials" setting doesn't make a difference.
Rocket.Chat then either uses the username or Full Name in LDAP as source.
It's noteworthy, that in my case the username is nearly identical to the Full Name.

Server Setup Information:

• Version of Rocket.Chat Server: 0.58.1
• Operating System: Debian 9.1 Stretch
• Deployment Method(snap/docker/tar/etc): tar
• Number of Running Instances: 2
• DB Replicaset Oplog: Yes, 1 ReplicaSet
• Node Version: 4.8.2

Steps to Reproduce:

1. Create LDAP user with Full Name like "User User-Name"
2. Sign in to Rocket.Chat using this user.
3. Avatar gets auto-generated.

Expected behavior:

Should be "UU" in this example.

Actual behavior:

But is "UN" in this example.

Any idea why ?
Thanks for your answers!

No file or test is named. Start by tracing the LDAP sign-in path into automatic avatar generation, then compare how the username and Full Name are selected for initials. Done means the reproduced ActiveDirectory example generates the expected initials, such as UU rather than UN.