Unfortunately each plain (stock) Android (except Nougat and above) seems to have this issue.
Fairphone would have to change that on their own in order to solve this, but I doubt they would get further permission from Google to distribute their OS afterwards. 
However, there are plenty of solutions available in the net that can be applied to rooted devices…
@Subhash , I just read you are on Open OS. Maybe you would like to give Lineage OS a try. 