RoonServer Running but can’t be connected to (Roon App fails to connect to the Core)

Roon Core Machine

Lenovo Yoga. i7-4500U CPU. 8GB memory.
Windows 10 Pro 64-bit 20H2 (Build 19042.1348)
Running Roon Server Version 1.8 (build 831) stable

Networking Gear & Setup Details

Core connected using Ethernet
Roon app running on my local laptop connected via Wifi
RPi4 running RopieeeXL connected via Wifi
Netgear router.

Connected Audio Devices

RPi4 running RopieeeXL 4.017 stable connected to an Oppo 105
Running Roon Bridge Version 1.8 (build 814)

Number of Tracks in Library

~2000

Description of Issue

Sometimes when I start Roon on my laptop (running Roon App Version 1.8 (build 831)), it cannot connect to the Roon Core. I have been running Roon in this configuration for over a week with no issues and this started happening yesterday.
When it does happen, I can still ping my Roon Core Machine and I can connect to it using Remote Desktop Connection.
I can also ping my laptop from the Roon Core Machine (logged in using Remote Desktop Connection).
If I kill the Roon Server task in Task Manager on the Roon Core Machine and restart it, then my laptop can find the Roon Core.
This points to a Roon Server responsiveness issue more than a networking issue.
Is there a way for me to diagnose what is going on with Roon Server? If there a server log file I can look at or logging that I can turn on?
I’m happy to track down the issue (and reasonably pc literate) I’m just new to Roon as so not sure where to start
thanks
mark

Some managed Netgear switches (and routers?) do IGMP snooping in a way that breaks Roon device discovery. Turning off IGMP snooping on their control Web interface typically solves the issue.

Thanks I will take a look at that.