I tested today while being at home the below setup:
iPhone 8 Plus + Tidal connected to Cambridge Audio CXN via AirPlay for about 1h, stressing continuously my iPhone via different applications (Instagram, Facebook, Reeder, Safari etc) and switching between cell phone operators in order to trigger a bad streaming behaviour => no interruptions
iPhone 8 Plus + Tidal connected to Poly (set at WiFi HotSpot) with the hybrid mode set up (LTE network enabled) => occasional breaks in streaming and I saw again the song buffering interruption issue
To me it is clear the issue is not caused by my phone doing handovers between the LTE cells, as I was standing static in my apartment.
The problem appears when I unlock the screen. When I browse through Reeder. When I browse sites on Safari, too!
It's not Apple's code that has issues, but:
1. Poly is either under-dimensioned (from the processing power point of view => the symptoms might be fixed via a SW tuning, therefore a new HW revision has to be done on Poly with a better processing unit);
2. or Poly is under-dimensioned (from the memory buffer point of view => the symptoms cannot be fixed via SW, therefore a new HW revision has to be done on Poly with a more larger memory buffer chip);
3. or Poly it's missing the buffering implementation for AirPlay (maybe can be fixed via a SW update);
4. or the buffer implementation is incorrectly being done in Poly's SW (it can be fixed via a SW update and that I don't know when it will come);
5. internal clock synchronisation issues related to Poly hardware (can be fixed via HW moods or hacks in house, at Chord Electronics, under product's standard warranty)
I am unable to play consistently the songs via AirPlay with the latest Poly version, therefore I will return my Poly to the dealer and I hope that they will understand that the Poly product is still immature and buggy, although on Roon it works perfectly. Unfortunately that's not my use case while I am on the move, therefore I use AirPlay.
Poly is available for two years on the market, according to the current thread, which makes me even more determined to ask for a refund, since this issue has not been fixed (or it has a fix only via a Poly HW revision update).
I understand everyone's enthusiasm about Poly when it comes about Roon and other use cases, but now I understand that AirPlay's implementation fails to show Poly as being a mature product and now Chord Electronics has to work on this to fix it. I also hope that Chord will appreciate the time I've put into troubleshooting this issue along with my feedback (which is a constructive one).