In my "Settings > Version Control > Ignored Files" list I have ignored Directory: .idea/
For a while it was working, but after the latest update to PHP Storm it has stopped ignoring this directory and its files and will try and add them to the git repository when I "Git > Add" from the root
From the "Help > About"
Build #PS-191.6183.95, built on March 27, 2019
JRE: 1.8.0_202-release-1483-b39 amd64
JVM: OpenJDK 64-Bit Server VM by JetBrains s.r.o
Windows 10 10.0