WITH clause in combination with EXISTS throws null pointer

The following query (simplified) throws a null pointer exception in the Teiid Springboot Starter 1.6.0:

WITH securityTable AS (SELECT securityRole FROM securityRoles)

SELECT * FROM multipleTablesAndSomeJoins AS mtsj
WHERE EXISTS (SELECT  securityRole FROM securityTable WHERE securityRole = mtsj.securitySector);

The securityRoles table is a TextTable that parses a UDF which gives the securitycontext of a user.

Removing the WITH clause solves the problem. Replacing the EXISTS clause with e.g. IN also solves the problem. However, we don't get the performance we want.

Original question on stackoverflow:

https://stackoverflow.com/questions/65039062/teiid-not-performing-optimal-join/65116799

This is the first Jira ticket I place here if I missed something please let me know.