Missing tables in menu with Firebird (V 2.5)

[SolarRadeon]

I have a database on Firebird 2.5 with 763 tables, but the navigation menu in Antares only shows 133 of them.

I have tried to manually list the tables using:
https://stackoverflow.com/questions/21765586/how-do-i-get-a-list-of-tables-from-a-firebird-database

SELECT a.RDB$RELATION_NAME
FROM RDB$RELATIONS a
WHERE COALESCE(RDB$SYSTEM_FLAG, 0) = 0 AND RDB$RELATION_TYPE = 0

^ The first answer gave the exact same incomplete list.

SELECT RDB$RELATION_NAME FROM RDB$RELATIONS
WHERE (RDB$SYSTEM_FLAG <> 1 OR RDB$SYSTEM_FLAG IS NULL) AND RDB$VIEW_BLR IS NULL
ORDER BY RDB$RELATION_NAME;

^ The second answer gave the expected result.

For debugging purposes I migrated the database format to Firebird 5 and there, the problem was not present.
(Both previously mentioned SQL commands gave the right number of tables, with the difference of (2) being sorted.)

Client: Arch based Linux | flathub Antares 7.25 | AUR debian package Antares 7.28 (both with the same results)
Server: Firebird 2.5 on Windows 7
Test server: Firebird 5 on Windows 10

I could provide screenshots, but I doubt it's necessary.

Personal note:
To make Firebird 5 server work with Antares, use settings from https://stackoverflow.com/questions/67895153/migrate-firebird-2-5-to-4-0-using-ado-net-provider#answer-67967784