SQLCODE: -99 when executing dynamic SQL on specific properties

Hi, I am unsure how to remove this restriction; when I am performing dynamic SQL using ##class(%SQL.Statement).%ExecDirectNoPriv(, .query, args...)

It works fine, but the moment I add specific properties from the persistent class I am performing the select on into the WHERE clause, I get: ERROR #5540: SQLCODE: -99 Message: User UnknownUser is not privileged for the operation. Despite using %ExecDirectNoPriv, I've tried with prepared statement as well, exact same situation.

I have read that it is possible to set privileges on individual properties on a persistent class, but I have no clue where to remove or change these privileges; the only solution I found is to add the role %All to UnknownUser, but that is not a fix but despite attempting to add full privileges for the persistent class for UnknownUser, I keep getting this privilege error.