Cannot (easily) close opened email attachment in Manager

1

Desktop version 22.8.6.249 on Windows 10.
In the emails tab I choose an email with an attachment. After opening the attachment I cannot see a way to close it without closing Manager completely, and then reopening Manager. The workaround is to open the attachment in a new Window.
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2

What if you press the Backspace ?

3

I had tried that, but no luck either.