Hello!
I’m just facing this bug, you can try reproduce it:
Firstly, create some folder on your HD with random sprite (like a sprite with red color).
After:
1–create a new object
2–add the sprites from folder (red sprite) as animation
3–save the project
4–close gdevelop
And change the red sprites to green one without change the name of them, just modify the colors of images.
5–reopen the project
6–try to change the sprites from red to green ones.
7–delete all red sprites e try to upload the green, you will noticy the icon of files are still as the red ones.
8–you chose the files to load and see that gdevelop opens the old ones (red sprites and not the updated to green).
Tested over Ubuntu 20.04 GDevelop 5.5.243
NOTE:
–the editor only reads files without bug if you put a different name on each file, but if you use old ones, the old files will be loaded.