We are preparing to migrate from Firebird 2.5 to 3.0.
We encountered strange behaviour when connecting from Java using latest Jaybird 3 (also tried latest 4.x) to Firebird 3.
All test users can connect fine except two users. I installed fresh Firebird 3.0.7 on separate server and initialized new security DB and created those two specific users. Without any luck.
Connections from isql, PHP7, IBExpert work just fine. Connections fail only from Java.

Steps to reproduce:
1. connect to any Firebird 3 database using Srp/Srp256 authorisation.
2. Execute statement:
CREATE USER "DAVIDS" PASSWORD 'aaa123' ACTIVE;
3. Using Java(Jaybird) try to connect to this DB with user "DAVIDS" and password "aaa123"
4. Result:
java.sql.SQLInvalidAuthorizationSpecException: Your user name and password are not defined. Ask your database administrator to set up a Firebird login. [SQLState:28000, ISC error code:335544472]

Firebird 3.0.7 (on Linux x64)
Openjdk 15
Jaybird 4.0.1 and Jaybird 3.0.9