Audio issues with Frame Rate 62.500 high bitrate

Hello, I noticed this issue with my Z9S, connected to my AV Pioneer VSX-923.
Movies with audio Dolby Digital Plus: many of them are correctly played and audio 5.1 is sent to speakers but some others have the following problem. If played with Pioneer "on" and sound sent to 5.1 speakers I have no audio (while video is perfect). If I switch off the Pioneer (audio is sent pass through to TV) audio is OK and obviously comes from TV only.
I checked the files and noticed that the difference between the ones working and the ones giving no audio is:
- Frame rate: 31.250 and lower bitrate (640kbps or lower) AUDIO OK on Pioneer showing "Dolby Digital Plus"
- Frame rate: 62.500 and higher bitrate (1472 kbps or 1536 kbps) NO AUDIO from Pioneer and its display keeps blinking without showing any indications.
Other parameters are the same in both the cases (A_EAC3, bitrate constant, 6 channels, Dolby Digital Plus, Compression lossy..).
Is this a limit of the Pioneer or of Zidoo? Or are there any settings to be changed in order to fix it?
Thank you in advance
BigSimon

 

The Zidoo supports HDMI 2.0a and the Pioneer only HDMI 1.4 so I'd say this a limitation of the Pioneer even though technically HDMI 1.4 should cope with 1536Kb/s.

If you want to send me a sample video I can test a Z9S on a receiver I know will support it and see if it works.