No ringing after PC sleep

[Vahur]

If 3CX Windows Client (diffrerent versions, currently v 15.5.12227.5) is running when PC (different devices, Windows 10 64bit, different builds) goes to sleep, then after waken client seems to be on normal state, but it will not ring nor showing any incoming call anymore. Calling out is possible. Only solution to get incoming calls is close it and restart client again.