controlnet always sends "both" preprocessor images while having hires.fix activated, in ui and via api, instead of chosen setting

[dermesut]

the generation of an image with the help of a controlnet unit, while having hires.fix activated, results in 3 images: 1 txt2img-result and 2 images that are the low-res and the hi-res version of the preprocessor image.
no matter, which setting i choose in "hires-fix option", i always get both.
this also is the case when generating an image via api and setting up the payload accordingly.
any idea what might be causing this?