If attachment save takes a while before erroring, progress window disappears without showing red X

[AbeJellinek]

e.g. https://ieeexplore.ieee.org/document/10556480

The progress window shows the PDF in gray while it tries to download it, and then after the failure, it immediately hides instead of showing the red X. I assume this is because the progress window hide timeout expires while the PDF is still downloading.

I've noticed this happening for a while.