Comments created via E-Mail in ServiceDesk Project are always internal after editing

Steps to reproduce:

1. setup jira 7.2.1 with jsd 3.2.1 and jeti 7.0.25

2. create incoming jeti mail handler

3. setup Service desk mail handler to create or comment

4. set flag to comments always visible

5. comment as customer via mail

6. edit this comment as agent, chose "share with customer"

Expected result:

comment is visible for customer

Actual result

comment is marked as internal and no chance to change