TYPO3 Core

having References to formPersistenceIdentifier from custom table, e.g.:

mysql> select tablename,softref_key,flexpointer,ref_table from sys_refindex where softref_key  like '%form%';
+--------------+---------------------------+------------------------------------------------+-----------+
| tablename    | softref_key               | flexpointer                                    | ref_table |
+--------------+---------------------------+------------------------------------------------+-----------+
| tt_content   | formPersistenceIdentifier | sDEF/lDEF/settings.persistenceIdentifier/vDEF/ | sys_file  |
| tx_b13_items | formPersistenceIdentifier | sDEF/lDEF/settings.persistenceIdentifier/vDEF/ | sys_file  |
+--------------+---------------------------+------------------------------------------------+-----------+

(here "tx_b13_items" is my custom table)

Click "Form" Module in Backend to "Form Management"

the Form is listed with 2 References, click the "2" in the Reference Column, only one reference is shown (the one to tt_content)

this happens because on SQL-Query for count reference have no constraint to "tablename" column, but SQL-Query for fetching references by form-identifier have constraint to "tablename='tt_content'"