Help for me, money for you.

Here are some potential fixes:
1. Check Roon Ready Settings: Ensure your Bryston preamp is in “Roon Ready” mode via its web interface and that it is selected as a playback device in Roon’s Audio settings.

2. Network Issues: Poor multicast handling or network conflicts can prevent Roon from detecting devices. Ensure your Bryston and Roon Core are on the same network and connected via Ethernet if possible.

3. Restart Devices: Restart both the Bryston preamp and the Roon Core to refresh connections.

4. Firmware Updates: Confirm that your Bryston preamp’s firmware is up to date, as outdated software can cause compatibility issues.

Call Bryston.  They’ve got great customer service/support and may pinpoint the issue quickly and save you a lotta time and hassle.  That’s what I’d do.  Best of luck. 

Look at Bryston for connectivity issues. Not all manufacturers devices are truly Roon ready.

Force a rescan of your Roon library. Go to settings-storage-click onl the 3 dots next  to your storage location and force a rescan.

Playlist, if it doesn’t come back after a rescan, probably a user error.

I’m sorry that the OP is having trouble and feel his pain.  Everytime someone posts asking about recommendations for a new CD player they are inundated with posts implying that they are crazy that they haven’t exclusively gone to streaming.  This is a great example of why hanging on to CDs and a player is a good idea 

Save the $80 and take your Mrs. to lunch with it. I'm certain the learned good folks here will be happy to help sans monetary payment. Nice gesture, though.

So I recommend not using the onboard core.  I have an Innuos Zenith MK3 (not in use right now) and the core is not implemented well.  I used an external ROCK core (which I'll be listing for sale soon) which sounded much better.  Innuos works better with the Sense ap, but I like roon, so I've moved to a Grimm.

I wouldn't expect roon to see my preamp, normally it sees the streamer that feeds the DAC.  Set up your Innuos as the endpoint and then it will feed your DAC.  Remember, whatever you want to be your "zone" has to be set up as an endpoint so reinstall the endpoint.

Jerry

You said "At one time, the system worked flawlessly but problems arose."  Roon does automatic backups.  If you have a backup dated when it worked flawlessly, try a restore of the backup.

 Ha!  Im with mahler123..

Have you tried the excellent Roon forum(s)? It’s called Roon labs community Help Often a Roon employee will help you. 

Usually when this stuff happens, something has changed. So what changed? Do you have autoupdate turned on? Did it do an update? 

Before you do anything else, have you redone all connections, and of course "did you reboot?" 

If you did get an update, see if you can roll it back, then turn off autoupdate. When things are working, never do an update unless you need something the update provides. Updates on anything that is working can be a dice roll. 

I know nothing about streaming, don't care to. But... the equipment does have computer chips in them I'm sure.

Anything with a chip, when things go awry, reboot it after unplugging for 20 minutes. Works 99% of the time. Some things have to be done on a regular basis to avoid issues. Examples: Roku for the TV, internet modem and router etc.

@toddstr

20 minutes is a bit excessive.  You just want to make sure the device switches fully off to ensure it reboots.

20 minutes is a long time on the Internet.  It is estimated that a new device plugged into the Internet will be attacked within 15 seconds.  Every device with a computer chip is vulnerable.  If it can be updated over the Internet, it can be attacked over the internet. As we recently discovered, popular systems like Windows need security updates several times a day.  Occasionally these updates are not benign!

20 minutes is a third of a CD.  I'd rather be listening than waiting!

@george4471

If I understand correctly your bryston preamp has a built in dac and your innuous connects to it via USB?

If that’s the case, I recommend the following-

1. Power everything off - shut down completely, nothing should be in stsndby

2. power on your preamp and let it boot up

3. Only after the preamp is up and running, power on your innuous

Check if roon sees the bryston. If not, go to roon settings, devices. See if your bryston preamp shows up there. Make sure to enable it.
If it doesn’t show up, it’s a different problem to troubleshoot.