Hello @benjamin,
I have uploaded a 1 minute test recording, which playes in Roon, but not with Roon ARC.
Recorded from
https://st03.sslstream.dlf.de/dlf/03/high/aac/stream.aac
than patched with
ffmpeg -i filename.aac -bsf:a aac_adtstoasc -codec: copy filename.m4a
to make it compatible with Roon.
Thanks for digging into this issue.
/Christoph