Android app getting wrong userhandle

[LordSexy]

useraccount= @user@domain.de

Steps to reproduce the problem*

1. Make new instance using docker compose (v4.5.5)

2. Use
   LOCAL_DOMAIN=domain.de
   WEB_DOMAIN=mastodon.domain.de
   because you have also matrix and other stuff on domain.de.

3. Got to browser. URL: https://mastodon.domain.de/@user looks good. When you click on the servername to copy the complete handle you get @user@domain.de

4. go into the android app. Add account, search for server domain.de --> it suggests "mastodon.domain.de" --> login, check profile

Now your handle is @user@mastodon.domain.de
...
Expected behaviour*

Respect my choice in localdomain and webdomain like the website and give my correct handle @user@domain.de

What should have happened?
This

Actual behaviour*
@user@mastodon.domain.de

I copied the format from mastodon/mastodon because I like the "format of the issue". Hope this makes it more clear.

And dont be shy to throw the fattest RTFM into my face. Tell me where I missed which setting and where to look it up.
contact me and Ill give you my adress. Dont want to post it publicly