You can try logging in manually from the CLI to check whether it works:
cd ~/.local/share/harbour-bitsailor/harbour-bitsailor/./bin/bw config server https://bitwarden.euBW_CLIENTID=<your-client-id> BW_CLIENTSECRET=<your-client-secret> ./bin/bw login --apikey
Replace <your-client-id> and <your-client-secret> with the actual values. If any error pops up, that’s what’s preventing the login.