Not able to update issue via excel vba in Jira 3.3.3

[Dieter Pardon]

I'm able to use POST and Get in excel VBA. For post I use the trick to write dummy data to user agent.
But I'm not able to use the PUT request.
In API browser, all goes well. Coding exactly the same in excel is not working.

This is my the part of code:

With JiraAuth
.Open "PUT", "http://beleu-jira01:8080/rest/api/2/issue/SAND-872", False
.setRequestHeader "Content-Type", "application/json"
.setRequestHeader "Accept", "application/json"
.setRequestHeader "User-Agent", "xx"
.setRequestHeader "Authorization", "Basic " & UserPassBase64(J_usernamep, J_Password)
.send StoryData

Authentication is not the problem. When printing storydata, this is the string: { "update":{ "summary":[{"set":"TestUpdateOfIssueViaVBA"}]}}

This looks exactly the same than API browser. What am I doing wrong?