There is not a fix for that at this time.
Around 5pm today I checked my computer and had the following article show up on my Feedly account. I am posting this now to get it out to readers that may have not seen it and need some free help in freeing up some iPhone space and can delete photographs in a group instead of one at a time.
Here is the link to the article: Photo Fixer
That is not an affiliate link, therefore I do not make any money if you click the link or download the free app. I am passing this out as information only for those that need it. This lists a free app that can be downloaded from the Apple App Store.
From just a short few paragraphs I also found what takes place when taking pictures with my iPhone that causes duplicates and what they call "bursts". I take a lot of not all my iPhone photos using the HDR feature which results in duplicate photos.
I guess I should have read more in depth before using the new iPhone last summer ... but as usual I jump in from the start and use the phone like I have with the previous phone ... then learn things as I go or run into trouble.
So the article answers some other questions I had but it still will not do what I want, preventing photos downloaded from my camera to my computer from being automatically uploaded into my iPhone and iPad. I know how to prevent that but it also means I have to manually change settings each time when I download photos from my camera or from my iPhone to the computer.
I had a pretty busy day today and still am not finished. I may post later tonight or early tomorrow.