what is strange is that all tool used on my phone or computer don’t provides me the preview file of photo from fstop. also preview file from other stock gallery tool.

where are stored preview photo of fstop ?

in Android/data/com.fstop.photo/file/cache there are only 12 preview photo for around 2000 photos !
in sdcard : android/data/com.fstop.photo contains almost nothing.

it is strange.