Thank you for your post and welcome to the forums!
Have you already tried to factory reset your phone? As in some cases this could resolve the issue.
Dial *#7370# to hard reset your device. Hard reset will remove all settings and personal data off the phone, so remember to backup of your phone with Nokia Suite first.
As Akash_satpathi already advised, you could also try to reinstall your phone firmware using Nokia Suite (just select Tools > Software updates).
If the issue still persists, visit your local Nokia Care Point and let them have a look.
Let us know if this helps,