I have found an existing thread on the microsoft web site (
answers.microsoft.com) that seems to explain the same issue.
There is a bug report since 2013.
On the 12/7/15, there is someone who exhort Microsoft engineers to analyze the thread explanation and to try to reproduce the issue before answering in the thread

.
It is amazing !
Does anybody has :
- contact at Microsoft to make them move ?
- any workaround ?