I feel like 1.1.9 is getting better. My iPhone rings most of the time and when it doesn't ring, I immediately get a notification of a missed call, so at least I know I need to wake up the app for it to start ringing again. Still not 100% reliable and therefore still costing me the fees for an additional line running an android phone so my digits line will ring reliably.
I just replied to your PM. Are you still seeing the sluggish behavior today?