I’ve had a similar but slightly different issue but the resolution may be the same.
I use a Naim NDS and I was noticing that if I was playing a 24/192 track and the following track is in a different format playback would stop at the end of the 24/192 and it wouldn’t move on to the next track. I noticed this when playing a mixed format playlist from QoBuz.
I’ve discovered that if you add the following setting to the section of your Naim streamer in the config.xml file it overcomes the issue.
I wonder if your issue is similar as Roon Radio will be mixing formats too?
Here’s my section for my Naim NDS
Edit - I’ve noticed that the last 10 seconds of the track then get skipped. This only occurs when sending PCM, if you enable FLAC compression in Roon the problem goes away. I’m keen to avoid FLAC as there is a slight sound quality dip on Naim streamers due to the overhead of the decompression in the streamer, they work best with native WAV/PCM. I’ve posted on the lms-to-upnp forum to see if I can get an answer.