google photos

Once uploaded to Google Photos the image on iCloud or your phone should be quite independent of the copy on Google Photos. So, if it's not that has to be a setting on the Google product so you're best asking on one of their forums.

jharper8 wrote:

Hi I use Google photos, my iCloud is full and if I delete a pic from iCloud or my phone it disappears from Google, I was an android user and may go back at some point so want to just pay for google

Google photos isn't an Apple product.