I have a choice of demand services on my smart tv, Humax freesat box and Amazon Firestick. I have full functionality across all these platforms when accessing standard apps like YouTube, Netflix, Amazon plus of course All4,C5 and ITV hub--but there is one culprit which refuses to offer stable service ,even on standard settings-with hardly a viewing going by without experiencing a drop out or extended buffering.Yes--you've guessed it--BBC Iplayer.
Since there is nothing wrong with my internet speed, I have excellent wifi proven by good functionality across three different devices and all other apps working properly on those three devices-I am concluding that there is something amiss with Iplayer. Am I the only one experiencing this?
Is there someway this can be fed back to those responsible? I am absolutely convinced I am doing nothing wrong with my equipment, which-as explained is fully operational. I even get good stable functionality when using Iplayer on an iPhone and iPad.
Why though is Iplayer so unreliable on all three of my tv hub devices which play all other apps perfectly?
All suggestions most welcome.    

Sorry for the delay in response.
Thanks for reply-most interesting re BBCIplayer taking up more bandwidth.That's a new one on me.
It's just not practical using LAN with my room set up-and in any case I know it usually works with wifi--because I experienced excellent non buffering playback for over a year on my set up until this autumn. Re your other point re which device is delivering the poor performance-my BBC Iplayer buffering occurs on my tv, satellite box and Firestick-all 3.
All other apps on all 3 devices work perfectly at all times.