Duplicate Files Not Being Thrown Away or Overwritten

I have a Hazel rule to move images after being renamed and tagged. However, my rule states that if a file already exists hazel should throw away the file.
Sadly, no matter what I do the rule does not appear to work and my file (an image) has an incremental number added to it, which results in several copies in the target directory causing me issues.
The image starts off as My-New-IMG_0202.JPG and every step of the way the naming format persists until the rule runs, which sends a copy to an archive directory and then moves the file to the final directory for processing.
I can see there is a file in the directory already with the same name My-New-IMG_0202.JPG, and then My-New-IMG_0202-1.JPG appears and will increment -2, -3 etc.
Running a test rule on my MacBook with macOS High Sierra the rule seems to work just fine! However, I can't upgrade the system running macOS Sierra 10.12.6 where the issue resides.
Any advice or suggestions on how to resolve this would be most welcome, as I don't recall this being an issue previously. I just tested this with version 4.2.4, and the issue persists.
Hazel is running on macOS Sierra 10.12.6 where the problem is.
Thanks in advance.
Sadly, no matter what I do the rule does not appear to work and my file (an image) has an incremental number added to it, which results in several copies in the target directory causing me issues.
The image starts off as My-New-IMG_0202.JPG and every step of the way the naming format persists until the rule runs, which sends a copy to an archive directory and then moves the file to the final directory for processing.
I can see there is a file in the directory already with the same name My-New-IMG_0202.JPG, and then My-New-IMG_0202-1.JPG appears and will increment -2, -3 etc.
Running a test rule on my MacBook with macOS High Sierra the rule seems to work just fine! However, I can't upgrade the system running macOS Sierra 10.12.6 where the issue resides.
Any advice or suggestions on how to resolve this would be most welcome, as I don't recall this being an issue previously. I just tested this with version 4.2.4, and the issue persists.
Hazel is running on macOS Sierra 10.12.6 where the problem is.
Thanks in advance.