johnny It didn’t.
Kugelblitz I did your second suggestion. I went to the folder and this time, I was able to open the trash bin folder without any hassle. I found all the files that I deleted right there. I selected all the files and right click. I don’t have a “delete” option. Instead, I have a “send to trash bin” option. The problem is that as soon click that option, all the files disappear and reappear in the same folder because “I’m in the trash bin folder” Duh. So I’m in a loop situation.
I tried booting Ubuntu and navigate the Batocera USB to the Trash Bin folder as root with nautilus. I was able to delete all the files. They indeed disappeared, but the free space didn’t increase. There was no change in the SHARE size. I rebooted Ubuntu and did the same steps again. I found no files in the trash bin but I don’t have any free space. I deleted 8 GB from the trash bin folder, but somehow it still there. Maybe the files went to another location. I think this is a bug.