What is the issue?
PDF/UA > Metadata and Settings > Document Settings > Display of document title in window title > DisplayDocTitle key is not set to true
What does it mean?
The file name is set as the window title.
How to fix it?
Use the task pane Settings in axesPDF. Click the button Defaults so that the standard settings for accessibility are determined in your document. Now the document title is set as the window title.