diff --git a/backend/src/apis/humhub/model/AbstractUser.ts b/backend/src/apis/humhub/model/AbstractUser.ts
new file mode 100644
index 000000000..8f876f053
--- /dev/null
+++ b/backend/src/apis/humhub/model/AbstractUser.ts
@@ -0,0 +1,23 @@
+import { User } from '@entity/User'
+
+import { PublishNameLogic } from '@/data/PublishName.logic'
+import { PublishNameType } from '@/graphql/enum/PublishNameType'
+
+import { Account } from './Account'
+import { Profile } from './Profile'
+
+export abstract class AbstractUser {
+  public constructor(user: User) {
+    this.account = new Account(user)
+    this.profile = new Profile(user)
+    // temp fix for prevent double usernames in humhub, if the username ist created from initials
+    const publishNameLogic = new PublishNameLogic(user)
+    if (publishNameLogic.isUsernameFromInitials(user.humhubPublishName as PublishNameType)) {
+      this.profile.firstname = this.account.username
+      this.account.username = user.gradidoID
+    }
+  }
+
+  account: Account
+  profile: Profile
+}
diff --git a/backend/src/apis/humhub/model/GetUser.ts b/backend/src/apis/humhub/model/GetUser.ts
index 7d9814fc3..8f50c8676 100644
--- a/backend/src/apis/humhub/model/GetUser.ts
+++ b/backend/src/apis/humhub/model/GetUser.ts
@@ -1,19 +1,15 @@
 import { User } from '@entity/User'
 
-import { Account } from './Account'
-import { Profile } from './Profile'
+import { AbstractUser } from './AbstractUser'
 
-export class GetUser {
+export class GetUser extends AbstractUser {
   public constructor(user: User, id: number) {
+    super(user)
     this.id = id
-    this.account = new Account(user)
-    this.profile = new Profile(user)
   }
 
   id: number
   guid: string
   // eslint-disable-next-line camelcase
   display_name: string
-  account: Account
-  profile: Profile
 }
diff --git a/backend/src/apis/humhub/model/PostUser.ts b/backend/src/apis/humhub/model/PostUser.ts
index a164440fd..b63c038cf 100644
--- a/backend/src/apis/humhub/model/PostUser.ts
+++ b/backend/src/apis/humhub/model/PostUser.ts
@@ -1,16 +1,7 @@
-import { User } from '@entity/User'
-
-import { Account } from './Account'
+import { AbstractUser } from './AbstractUser'
 import { Password } from './Password'
-import { Profile } from './Profile'
 
-export class PostUser {
-  public constructor(user: User) {
-    this.account = new Account(user)
-    this.profile = new Profile(user)
-  }
-
-  account: Account
-  profile: Profile
+// only add password as filed, rest the same as AbstractUser
+export class PostUser extends AbstractUser {
   password: Password
 }
diff --git a/backend/src/data/PublishName.logic.ts b/backend/src/data/PublishName.logic.ts
index d3643d633..e49c3e73a 100644
--- a/backend/src/data/PublishName.logic.ts
+++ b/backend/src/data/PublishName.logic.ts
@@ -67,17 +67,25 @@ export class PublishNameLogic {
    *   else return user.firstName[0,2] + user.lastName[0,2] for publishNameType = [PUBLISH_NAME_ALIAS_OR_INITALS, PUBLISH_NAME_INITIALS]
    */
   public getUsername(publishNameType: PublishNameType): string {
-    if (
-      [
-        PublishNameType.PUBLISH_NAME_ALIAS_OR_INITALS,
-        PublishNameType.PUBLISH_NAME_INITIALS,
-      ].includes(publishNameType)
-    ) {
-      return publishNameType === PublishNameType.PUBLISH_NAME_ALIAS_OR_INITALS && this.hasAlias()
-        ? this.filterOutInvalidChar(this.user.alias)
-        : this.firstUpperCaseSecondLowerCase(this.filterOutInvalidChar(this.user.firstName)) +
-            this.firstUpperCaseSecondLowerCase(this.filterOutInvalidChar(this.user.lastName))
+    if (this.isUsernameFromInitials(publishNameType)) {
+      return this.filterOutInvalidChar(
+        this.firstUpperCaseSecondLowerCase(this.user.firstName) +
+          this.firstUpperCaseSecondLowerCase(this.user.lastName),
+      )
+    } else if (this.isUsernameFromAlias(publishNameType)) {
+      return this.filterOutInvalidChar(this.user.alias)
     }
-    return this.hasAlias() ? this.user.alias : this.user.gradidoID
+    return this.user.gradidoID
+  }
+
+  public isUsernameFromInitials(publishNameType: PublishNameType): boolean {
+    return (
+      PublishNameType.PUBLISH_NAME_INITIALS === publishNameType ||
+      (PublishNameType.PUBLISH_NAME_ALIAS_OR_INITALS === publishNameType && !this.hasAlias())
+    )
+  }
+
+  public isUsernameFromAlias(publishNameType: PublishNameType): boolean {
+    return PublishNameType.PUBLISH_NAME_ALIAS_OR_INITALS === publishNameType && this.hasAlias()
   }
 }
diff --git a/backend/src/graphql/resolver/UserResolver.ts b/backend/src/graphql/resolver/UserResolver.ts
index 0302c7860..4e1504b02 100644
--- a/backend/src/graphql/resolver/UserResolver.ts
+++ b/backend/src/graphql/resolver/UserResolver.ts
@@ -34,6 +34,7 @@ import { updateGmsUser } from '@/apis/gms/GmsClient'
 import { GmsUser } from '@/apis/gms/model/GmsUser'
 import { HumHubClient } from '@/apis/humhub/HumHubClient'
 import { GetUser } from '@/apis/humhub/model/GetUser'
+import { PostUser } from '@/apis/humhub/model/PostUser'
 import { subscribe } from '@/apis/KlicktippController'
 import { encode } from '@/auth/JWT'
 import { RIGHTS } from '@/auth/RIGHTS'
@@ -170,9 +171,9 @@ export class UserResolver {
     let humhubUserPromise: Promise<IRestResponse<GetUser>> | undefined
     const klicktippStatePromise = getKlicktippState(dbUser.emailContact.email)
     if (CONFIG.HUMHUB_ACTIVE && dbUser.humhubAllowed) {
-      const publishNameLogic = new PublishNameLogic(dbUser)
+      const getHumhubUser = new PostUser(dbUser)
       humhubUserPromise = HumHubClient.getInstance()?.userByUsernameAsync(
-        publishNameLogic.getUsername(dbUser.humhubPublishName as PublishNameType),
+        getHumhubUser.account.username,
       )
     }