Hi esimsnl,
I'm Sumit, here to answer your query at the Microsoft Community.
Via: https://support.microsoft.com/topic/troubleshoo...
Make sure your PC and Android device are both nearby, turned on, and connected to the same Wi-Fi network
Secondly, remove Phone link App from your Phone and reinstall again.
Third, perform an App Reset of Phone link by right-clicking the app, and choosing App Settings>Reset and then start over.
Also, let us know if you are using Samsung device - the steps might be different for that.