Quick view question

[homersimpsonmeingmx]

Hello,

when looking at pictures with the quick view, a stripe appears at the bottom of the image. It is empty and its function is not clear to me (see picture https://ibb.co/1Z0t3W0).
I tried to deselect "Show frames" in the context menu as well, but nothing happens, the stripe remains and the next time "Show frames" is again checked (why?).
(What should do "Show frames" indeed?).
With text, videos or other files the stripe is not visible. Only with images.

How can I get rid of it?

I try with a fresh portable 810 on Win10 1903.

Regards, Marco