Successful completion of a SCORM Project using Micorsoft Edge

Dear community members,

it's my first post here and I hope, someone of you can answer my question. Thanks in advance for reading and thinking about a possible solution:

I have created a project in Captivate importing a PowerPoint presentation. For switching back and forth through the pages I use a default playbar from the Skin Editor with the required buttons. The possibility to navigate to the next pages by mouse click in the click field is deactivated. So I want the Users to only use the playbar for navigation.

The Project has been zipped and uploaded to a LMS. The settings of the project are, that the users have to watch 10 out of 14 pages to successfully complete the course.

The problem is now: Using Microsoft Edge, watching at least 10 pages and close the browser window won't turn the course to "complete". I still get an "incomplete" trying different scenarios in MS Edge.
The only possible option getting the course completed is watching at least 10 pages and close the window with the close button which is integrated into the playbar. In my opinion a browser window usually will be closed using the "x" in the top right corner of the browser window. Not using a "x" integrated in a playbar.

It is noticeable that the whole course works fine in other browsers such as IE or Firefox -> watching at least 10 Pages, closing the browser window using the "normal" close button, getting the course completed.

Do you have any idea how to change the behavior, so that the course also gets completed closing the browser window in conventional way.
Do you have an idea, where this problem could be located and solved? Settings in Captivate? Problem caused by the LMS? Or a browser issue?

Thanks again in advance! Any hints are very much appreciated.

BR, Christian