Every time I use batch function to rename files, PS saves an additional photo with a diff name

I'd look closely at the action this batch is running. You can't batch without an action to batch, and I bet there's a save a copy in there somewhere, with a certain file name and location recorded.

It sounds like you'd probably be better off with Image Processor.

Already uninstalled and reinstalled. Still happening. 

Try to reinstall it. 

Bit of an odd one. I use the batch function to resize and rename files every day. Today photoshop has started saving a copy of one of the photos (always just one, even when I'm processing hundreds of images) in a different file location to where I have designated (again, photoshop is always saving into the same folder no matter where I have it actually pointing towards), and saving it under the exact same name, regardless of what I have set as the naming convention. 

 

EG. I am processing 50 files in location x and asking them to be resized and renamed in the convention NAME_01 and saved in location x. 

 

Photoshop seems to randomly choose 1 file, save it in location y and call it DIFFERENTNAME_01. Always the same name, always the same location, always just one file. Also it's a very specific name that is quite likely to be a file name I've used in the past. 

By @Ciara270257893brn