Howdy @denizbilgin!
Many of our customers are able to use Detox on Bitrise and we do offer some best practices. With that said, we don’t officially support Detox. There’s a limit to the scope of support we can provide, although we do make a best effort to help.
I have two suggestions. First, if you haven’t read through our Detox documentation I suggest that you check it out: https://devcenter.bitrise.io/testing/running-detox-tests-on-bitrise/
Second, a lot of folks aren’t aware that the Android Emulator needs to be started in two steps:
Make sure you have both of them in your workflow or the Android Emulator may not work as expected.