I have Kef LSX loudspeakers and use Roon with Tidal and Qobuz. It looks like it’s playing through AirPlay and the res is 24/44. I thought Roon would bring it up at least to 44/92.
Lsx only supports Kef streaming or airplay. You should have an option I Roons audio settings to add them using Kef streaming, sounds like you added them as an Airplay client. You have to choose the protocol you want when adding a device as a Roon endpoint as it will give you all the options the device advertises and Roon supports. If your not seeing Kef streaming ensure your on latest firmware and they are on the same network as each other.
I believe I’ve read on the Audirvana forums that Airplay is limited to 24/48 max. I don’t have Airplay so I can’t test it.
It supports 44.1 for audio currently nothing higher. When using the LSX you can use Kef streaming which will get you to 96/24 or Airplay Sounds like the Op has not configured them to use Kef streaming so will be limited.