Photoshop action works fine, but when I create a droplet, it adds an extra photo.

Ohh perfect. I'll try this now 🙂 Thanks for your help. I'll let you know how it goes!

Export Save for Web (Legacy) isn't the same thing as Save As. It would be helpful if you expanded the export step and made the panel wide enough to view all content in the recording.

Ohhh I had no idea, apologies! When you say export step. Do you want to see the 'Save for web' box that it opens? Sorry, I'm really not that good with PS. I'll attach a photo of when I click 'Save for Web'. Thanks!! 

You have export step plus instruction to save document name with A,B,C suffix as I guess. Record Save As step and check Overwrite Save As commands in droplet creation dialogue. Do not forget to add extension after A,B,C...

Export Save for Web (Legacy) isn't the same thing as Save As. It would be helpful if you expanded the export step and made the panel wide enough to view all content in the recording.

Okay I'll try that. I think I included the droplet extension to be honest. I was worried about files getting overwritten so I just added that. I presume that maybe the mistake? Thanks

Thanks for getting back to me. I've attached the action and the droplet settings that I used. I'm not very good with PS so let me know if you need more info 🙂 Thanks 

You may want to recreate the droplet because the setup might be hard to recall. It appears that the Serial Letter (A, B, C) is somehow included in the droplet setup. However, I have not been able to reproduce it successfully.

Try to recreate the droplet and check if the error persists. A strange thing is that docnameA lacks an extension.

It would help if you posted screenshots of the action panel with all steps expanded/disclosed and also the droplet setup settings.