Videobridge - Health.doRun#300: Health check failed in 0ms

Hi,

I got Jitsi running on Ubuntu Server 18.04. It is on a private network, behind a firewall.

The jvb.log ist flooded with those messages:

[28] Health.doRun#300: Health check failed in 0ms:
java.lang.Exception: Address discovery through STUN failed
        at org.jitsi.videobridge.health.Health.doCheck(Health.java:138)
        at org.jitsi.videobridge.health.Health.doRun(Health.java:266)
        at org.jitsi.utils.concurrent.PeriodicRunnableWithObject.run(PeriodicRunnableWithObject.java:87)
        at org.jitsi.utils.concurrent.RecurringRunnableExecutor.run(RecurringRunnableExecutor.java:216)
        at org.jitsi.utils.concurrent.RecurringRunnableExecutor.runInThread(RecurringRunnableExecutor.java:292)
        at org.jitsi.utils.concurrent.RecurringRunnableExecutor.access$000(RecurringRunnableExecutor.java:36)
        at org.jitsi.utils.concurrent.RecurringRunnableExecutor$1.run(RecurringRunnableExecutor.java:328)
2020-04-14 06:30:49.366 INFORMATION: [27] VideobridgeExpireThread.expire#144: Running expire()

I do not need STUN when using Jitsi in a private network, or do I?
Can I disable those messages or is tihs a serious problem?

Edit:
oh… I got this message in the prosody.log

info    Authenticated as jvb@auth.SERVER-IP
jitsi-videobridge.SERVER-IP:component       warn    Component not connected, bouncing error for: <iq id='OOgmE-73' type='get' to='jitsi-videobridge.SERVER-IP' from='focus@auth.SERVER-IP/focus39406796
900'>

this looks serious?

Maybe read this: https://github.com/jitsi/jitsi-videobridge/issues/1198#issuecomment-614519133 ?