Unexpected Error: ORA-02054: transaction 94.44.4071354 in-doubt

Scenario
A transaction on a local and on a remote database fails at commit

The error:
Unexpected Error: ORA-02054: transaction 94.44.4071354 in-doubt

To see real error, check alert.log on the remote server.

The actual error is not propagated to the local server

Error 2091 trapped in 2PC on transaction 94.44.4071354. Cleaning up.

Error stack returned to user:

ORA-02054: transaction 94.44.4071354 in-doubt

ORA-02091: transaction rolled back

ORA-00001: unique constraint (USER_A.TABLE_A_UK) violated

ORA-02063: preceding 2 lines from REMOTE_DB