libcudnn7 for Cuda 10 being 'upgraded' on cuda 9.2 linux

Hi there, I had this issue this morning, on a routine update and upgrade on linux (ubuntu 16.04) I saw there were some updates on libcudnn7, installed them and it installed the upgrade for libcudnn7 but for CUDA 10, I had to remove those packages and download the .deb package and install from there, any ideas why would the update for CUDA 10 be installed even though I use Cuda 9.2?