NullPointer Exception when doing count aggregations on two individual columns from separate databases

I have issues doing Count aggregations in 2 different databases. 2 out of 3 following cases fail... (But distinct count seems ok)

<----------- CASE 1 ----------> SUM first, then COUNT => OK

SUM(DB_2.field_1), COUNT(DB_1.field_1)

select sum("FoodmartDataSourceJNDI_public_expense_fact"."amount") as "FoodmartDataSourceJNDI_public_expense_fact_amount_Sum",

count("FoodmartDataSource_public_employee"."full_name") as "FoodmartDataSource_public_employee_full_name_Count"

from "FoodmartDataSource_public"."employee" "FoodmartDataSource_public_employee"

inner join "FoodmartDataSourceJNDI_public"."expense_fact" "FoodmartDataSourceJNDI_public_expense_fact" on ("FoodmartDataSource_public_employee"."store_id" = "FoodmartDataSourceJNDI_public_expense_fact"."store_id")

SELECT g_0."store_id" AS c_0, g_0."full_name" AS c_1 FROM "public"."employee" AS g_0 ORDER BY c_0

SELECT g_0."store_id" AS c_0, SUM(g_0."amount") AS c_1 FROM "public"."expense_fact" AS g_0 GROUP BY g_0."store_id" ORDER BY c_0

<-----------CASE 2 ---------------> COUNT first, then SUM => ERROR

COUNT(DB_1.field_1), SUM(DB_2.field_1)

select count("FoodmartDataSourceJNDI_public_expense_fact"."category_id") as "FoodmartDataSourceJNDI_public_expense_fact_category_id_Count",

sum("FoodmartDataSource_public_employee"."salary") as "FoodmartDataSource_public_employee_salary_Sum"

from "FoodmartDataSource_public"."employee" "FoodmartDataSource_public_employee"

inner join "FoodmartDataSourceJNDI_public"."expense_fact" "FoodmartDataSourceJNDI_public_expense_fact" on ("FoodmartDataSource_public_employee"."store_id" = "FoodmartDataSourceJNDI_public_expense_fact"."store_id")

Caused by: java.lang.NullPointerException

at org.teiid.query.processor.relational.GroupingNode.initialize(GroupingNode.java:184)

at org.teiid.query.processor.relational.RelationalPlan.connectExternal(RelationalPlan.java:108)

at org.teiid.query.processor.relational.RelationalPlan.connectExternal(RelationalPlan.java:113)

at org.teiid.query.processor.relational.RelationalPlan.initialize(RelationalPlan.java:103)

at org.teiid.query.processor.QueryProcessor.init(QueryProcessor.java:194)

at org.teiid.query.processor.QueryProcessor.nextBatchDirect(QueryProcessor.java:130)

at org.teiid.query.processor.QueryProcessor.nextBatch(QueryProcessor.java:109)

at org.teiid.query.processor.BatchCollector.collectTuples(BatchCollector.java:153)

at org.teiid.dqp.internal.process.RequestWorkItem.processMore(RequestWorkItem.java:382)

at org.teiid.dqp.internal.process.RequestWorkItem.process(RequestWorkItem.java:291)

... 123 more

<-----------CASE 3 ---------------> COUNT on DB1.COL1 and COUNT on DB2.COL2 => ERROR

COUNT(DB_1.field_1), COUNT(DB_2.field_1)

select count("FoodmartDataSourceJNDI_public_expense_fact"."category_id") as "FoodmartDataSourceJNDI_public_expense_fact_category_id_Count",

count("FoodmartDataSource_public_employee"."first_name") as "FoodmartDataSource_public_employee_first_name_Count"

from "FoodmartDataSource_public"."employee" "FoodmartDataSource_public_employee"

inner join "FoodmartDataSourceJNDI_public"."expense_fact" "FoodmartDataSourceJNDI_public_expense_fact" on ("FoodmartDataSource_public_employee"."store_id" = "FoodmartDataSourceJNDI_public_expense_fact"."store_id")

Caused by: java.lang.NullPointerException

at org.teiid.query.processor.relational.GroupingNode.initialize(GroupingNode.java:184)

at org.teiid.query.processor.relational.RelationalPlan.connectExternal(RelationalPlan.java:108)

at org.teiid.query.processor.relational.RelationalPlan.connectExternal(RelationalPlan.java:113)

at org.teiid.query.processor.relational.RelationalPlan.initialize(RelationalPlan.java:103)

at org.teiid.query.processor.QueryProcessor.init(QueryProcessor.java:194)

at org.teiid.query.processor.QueryProcessor.nextBatchDirect(QueryProcessor.java:130)

at org.teiid.query.processor.QueryProcessor.nextBatch(QueryProcessor.java:109)

at org.teiid.query.processor.BatchCollector.collectTuples(BatchCollector.java:153)

at org.teiid.dqp.internal.process.RequestWorkItem.processMore(RequestWorkItem.java:382)

at org.teiid.dqp.internal.process.RequestWorkItem.process(RequestWorkItem.java:291)

... 123 more