No ring tone on inbound call from skype and Bria or Signal

[Superfly]

Installed Bria for sip calls, and the same issue is with Signal call and messaging app.  When the shell is closed and I get a call from these application mentioned above the call comes thru but only rings once and then goes silent as the inbound call is still active. 
If I get a regular call from a cell number the ring tones works as expected.

[ianisthewalrus]

i get that behavior even for normal calls...  maybe you are lucky.

[spa]

i get that behavior even for normal calls...  maybe you are lucky.

Is it about ringtone or vibration?
My Cosmo Communicator ringtone are normal. The vibration does not continue.
As for the vibration, CosmoCtl will fix it.