This odd issue happens on specific occasions. I've been trying to narrow down my observations and so far it fails to save photos that are pointed (and focused) on a computer screen.

There is no error message whatsoever, except for an indication that the pictures I took doesn't appear on the gallery thumbnail, Gallery (Simple Gallery), and File Manager (Simple File Manager). I've got plenty of space on memory too.

I get over this by spamming the capture button and eventually one of them would work. I tried different resolutions, disabling EXIF, none of which helped.

This issue never happened with its built-in camera app.

Honor 9 Lite (LLD-L21), Android 9, Simple Camera v5.1.1