If you done any mods on your Samsung Galaxy Fold 3 and want to roll back to latest official firmware, you can do so by following these steps. And since you are flashing official ROM on your Fold 3, you will not loose any warranty.
First, get latest version of ODIN on your computer. Make sure it is running Windows.
Download the latest ROM from here. You will find a SM-xxxxx_x_xxxxxxxx_xxx.zip.enc4, change the extension to .zip. Extract the file.
Fire up Odin. Turn off your Fold 3 and connect to the computer.
Click on BL and select BL_xxxxxxxxxx.tar.md5
Click on AP and select AP_xxxxxxxxxxx.tar.md5
Click on CP and select CP_xxxxxxxxxx.tar.md5
Click on CSC and select CSC_OMC_xxxxxxxxxx.tar.md5 – do this only if you want to change the CSC. Otherwise, do not select anything here.
Click on USERDATA and select HOME_CSC_OMC_xxxxxxxxxx.tar.md5
Click on Start to start the flashing process. Keep in mind that this process will delete everything stored on your Fold 3. This is a great way to remove all sorts of modifications you might have done on your android phone. It removes modifications and delete data, which is also useful if you are planning to sell the Fold 3.