You can use the software that you use as the startup disk. It has the function of returning the space of the USB disk, or it can also use the Chinese cabbage super USB disk startup tool
1. The software may have caused the partition confusion. 2. Solution: Format the USB stick. 3. If not, just find a tool for mass production. 4. It is suggested to reformat it with Rubik's Cube. Most of them can succeed.