Although some blogs have reported some trackers in Bitwaren, they are in fact not tracker. Here are some explanations provided by Bitwarden (please note we did not decompile the code to verify assertions).
Firebase and MS VS App Center
Although Firebase Cloud Messaging and Microsoft Visual Studio App Center, they are not used to track you.
As documented by Bitwaden on their web site https://bitwarden.com/help/security-faqs/#q-what-third-party-services,-libraries-or-identifiers-are-used-in-my-bitwarden-account, Firebase Cloud Messaging (often mistaken for a tracker) is used only for push notifications related to sync and performs absolutely no tracking functions.
Microsoft Visual Studio App Center is used for crash reporting on a range of mobile devices.
F-Droid build
For those who prefer to exclude all 3rd party communication, Firebase and Microsoft Visual Studio App Center are removed completely from the F-Droid build.
Additionally, turning off push notifications on a self-hosted Bitwarden server will disable using the push relay server.