Possible bug: Matrix reports broken in 7.6.2.1?

Does anyone else have issues with matrix reports in 7.6.2.1?

E.g.

Matrix report

Module: Calls

Filters:

Calls > Date Created [This Year]

Group By:

Calls > Assigned User > username

Calls > Direction

Display Summary

Calls > Assigned User > username

Calls > Direction

Calls > Count

No Chart options

No Optional Related Modules

Show SQL:

SELECT l1.user_name l1_user_name,IFNULL(calls.direction,'') calls_direction

,COUNT(calls.id) calls__allcount, COUNT(DISTINCT calls.id) calls__count

FROM calls

INNER JOIN users l1 ON calls.assigned_user_id=l1.id AND l1.deleted=0

WHERE (((calls.date_entered >= '2016-01-01 07:00:00' AND calls.date_entered <= '2017-01-01 06:59:59'

)))

AND calls.deleted=0

GROUP BY l1.user_name

,calls.direction

ORDER BY l1_user_name

ASC,CASE WHEN calls.direction='Inbound' THEN 0

WHEN calls.direction='Outbound' THEN 1 ELSE 2 END ASC

In MySQL Workbench select works fine, in output the username is not present in all rows and totals seem off.

thanks,

Francesca