specific user error on custom component

We created a custom component for the users settings which was working fine for a long time. But for some weeks now some users are complaining about that the widgets aren't loading on this specific page. We had a deeper look into it but we are not able to reproduce this issue either on stage nor on production.

So we created a test output for only admin users on production to call the users profile which have these issue. And for some reason we get an FreeMarker template error for these users, if we try a different user id everything is working as expected. We also compared the results from the restapi call but still have no clue what is causing the issue. All we’re trying to do is the following:

<#assign userProfiles=restadmin("/users/id/45993/profiles?restapi.response_style=json") />
<#assign profiles><@xmltohash xml=userProfiles.profiles.profile /></#assign>
<#assign profiles=profiles?eval />

The issue occurs on the third line:

FreeMarker template error (HTML_DEBUG mode; use RETHROW in production!)

Failed to "?eval" string with this error:

---begin-message---
Syntax error in ?eval-ed string in line 3, column 54:
Encountered "Kunden", but was expecting one of:
    ".."
    <DOT_DOT_LESS>
    "..*"
    ","
    "}"
    "."
    "["
    "("
    "?"
    "!"
    <TERMINATING_EXCLAM>
    "??"
    "+"
    "-"
    "*"
    "/"
    "%"
    "!="
    "="
    "=="
    ">="
    <ESCAPED_GTE>
    ">"
    <ESCAPED_GT>
    <LESS_THAN_EQUALS>
    <LESS_THAN>
    <AND>
    <OR>
---end-message---

The failing expression:
==> profiles?eval  [in template "custom.cb.settings-page" at line 248, column 21]

----
FTL stack trace ("~" means nesting-related):
    - Failed at: #assign profiles = profiles?eval  [in template "custom.cb.settings-page" at line 248, column 3]
----

Anyone an idea whats going on here?

Thanks in advance

Christian