With the recent PS update, a new edit starts as a 16 bit image. Thus, you cannot save the image as a jpg You need to go to mode and manually change it to 8 bit to save it in jpg,
Also, you have to use save as copy to save as a jpg. To revert to the old way using save as,
You have to go into preferences and check the legacy box and I would suggest checking the “don’t include the word copy” in the saved file name.
I have yet to find a way to have all images open in 8 bit so you don’t have to remember to change from 16 bit to 8 bit before you start your editing. If you know a way, please let me know.
I know adobe believes using save as copy prevents you accidentally overwriting your original image by mistake. I have never overwritten my original file because I use a different file name.