File without extention flickers and dosn't load
When trying to open files (tested on PNGs and JPEGs) without extention, gthumb opens a small preview and continuously flickers between the small preview and a placeholder image. The status bar at the bottom flickers as well.
However, if multiple image files (with or without extention) are present in the directory, pressing e.g. spacebar to advance to the next image, gthumb successfully loads the image and pressing backspace goes back to the flickering image that now is displayed without issues.
gthumb 3.8.0 - Debian testing, bullseye