Android App: Unable to resolve host

Hi all,

currently I’m evaluating bitwarden.
I’m having quite some trouble using the android app because it can’t resolve the hostname of my self-hosted installation. The used version is the latest one from the official playstore.
The exact error message is:
Exception message: Unable to resolve host "": No address associated with hostname.
The interesting thing is that I can copy the address on the same device and access the web UI in the browser.

Some information about my network:

  1. The issue happens on three different “devices” (2x android 11, 1x bluestacks 5)
  2. The server is hosted on docker and accessed via reverse proxy (using a self signed certificate for TLS that is imported to the android device)
  3. The DNS entry ( is only available internally, i.e. although it’s an official domain, the intranet zone is only available on my network.
  4. The DNS entry is a CNAME pointing to a A-record of the docker host.
  5. The DNS name is only available for IPv4 my network also has partially IPv6.

Similar setups work for quite some other applications, so I wonder what is different to the bitwarden app that it can’t resolve the hostname. Has anybody seen this kind of behavior already?