Slices - Save for web - don1t create JPG files

HI,
I'm using PS v25.9.1.
I create a PSD with slices and it's all ok. But when I use "save for web" selecting JPEG preset and after at "save Otpimized As" window the "Images Only" as format, "Default Setting" as Settings as "All Slices" as Slices, PS create the first file as a PNG one and the othes as a GIF files. So as I need the files as JPEG, I need to convert tem all.
I don't why this is happening and didn't find a settinf that can be my problem.
If anyone could help me, Tks!