HTTP BasicAuth -> .js Files not loaded on first request

Nextcloud version: 12.0.3
Operating system and version: Ubuntu 16.04.3 LTS
Apache or nginx version: Apache 2.4.18
PHP version: 7.0.22

Is this the first time you’ve seen this error?:
No

Can you reliably replicate it? (If so, please outline steps):

  1. Activate HTTP BasicAuth in Apache like this (ldap backend in my case):

     AuthType Basic
     AuthName "nextcloud"
     Require valid-user
     AuthBasicProvider ldap
     AuthLDAPURL ldap://....
    .
    .
    
  2. Open Nextcloud URL in browser

  3. Browsers BasicAuth Dialog appears

  4. Enter valid credentials

  5. Nextcloud takes BasicAuth User and so doesn’t show Nextcloud Login Form

  6. Nextcloud shows no menu and just partly the files app but no folders / content of files app

  7. With browsers Dev.Tools notice, that not even 1 single .js file was requested / loaded

  8. Do a simple page reload => Problem solved, nextcloud loads normally, everything works

  9. Notice during page reload with Dev.Tools: all .js Files are requested / loaded

The issue you are facing:
After logging in with Basic Auth the first page requests doesn’t load .js files, a page reload is needed.

Could it be that this has sth. to do with the “nonce” attribute in the - tags? I noticed that on the first request this is a different one as after the page reload request…