To report any issues you find please use this link, do not forget to provide as much info as possible. Please do not report the same issue if someone already reported it, this will only slow down our operations. If you remember the latest build where the issue didn't exist it would greatly help to track down what caused it. The following is an useful bug report format.
Phone model: ex. jfltexx or GT-I9505
Baseband version: ex. I9505XXUHOD7
ROM version: ex. 20160116
GApps Package: CM GApps [date] or Open GApps [type] [date] or Slim GApps [type] [date] ex. Open GApps Micro 20160116
Did you do a clean install for the currently installed build? yes/no
Did you reboot after having the issue? yes/no
Did you do any system modification? yes: [mod]/no
Did you flash another kernel? yes/no
Did you install Xposed framework? yes/no
(Superuser related issues only) Did you install SuperSU? yes/no