Roon keeps reducing sample rate conversion to onkyo receiver

Hi - I am new to Roon and initially very impressed - but I have invested in a large High Res music database - stored in Flac on my Synology DS213j NAS drive. I have an Onkyo TX 8270 receiver (chrome cast built in) connected by Ethernet to my Network ( Netgear Modem and TP Link router, and BT Whole Home Wifi Mesh)).Roon Core is on my Apple iMac 27 MNE92B/A All-In-One Desktop, Intel Core i5, 8GB RAM, 1TB Fusion, Radeon Pro 570, From an audio perspective everything works great 192 at 24 bit streams effortlessly , but the Onkyo app is very clunky for playlists etc.

I also have four Onkyo wireless NCP 302 speakers( chrome cast built in) , two old Bose speakers connected via chrome cast 2nd generation and a Samsung HW -K850 sound bar connected via chrome cast 2nd gen.
Roon recognises all these speakers and synchronises well but seems to reduce sample rate down for the Onkyo receiver - typically will reduce from 192 - 90 when linked to other speakers , but when connect on its own will reduce to 44.
Obviously as music quality is the first priority can’t see me keeping Roon beyond the trial stage if I can’t get it to send the full 192 file to my Onkyo receiver

Are you using Chromecast to stream to the Onkyo? If so, I think it automatically downsamples over Chromecast unless the receiving device says it can receive hi-res. Many audio systems with “Chromecast built-in” don’t seem to do that properly, and I’ll bet the Onkyo is one of them. Onkyo is all about the DTS Play-Fi; I don’t think they take the Chromecast stuff seriously. Might check for an Onkyo firmware update?

You coulld also get a streamer, like the Allo DigiOne, and stream into the Onkyo via its S/PDIF connectors. That should give you full resolution.

Turns out one is for sale:

My Onkyo TX RZ800 was visible on my Dlna network but wasn’t gapless, via JRiver etc so used a Cambridge Audio CXN then analogue to the Onkyo

When I went to Roon I soon invested in a RPi and Allo Digione And fed via Ethernet to the RPi and cox to the Onkyo

The Onkyo DAC was good so coax was fine up to 24 384 if I recall