Duplicate photos on my iPhone but not on iPad

Hi, I have an iPad and iPhone & use Google Photos & Google Drive to manage & store my photos & videos. All worked well until recently! The problem I have is that when I now take a photo on my iPhone , I get 2 copies . It does not happen when I use take photos on my iPad . I have tried uninstalling & reinstalling Google photos on both the iPhone phone & iPad & checking the storage settings but without success. As a result I have to delete the duplicate from the iPhone before I can create an album . Help please!