Idle server keeps restarting (considered dead by other servers)

This one server keeps restarting, apparently due to heartbeat
The other similar 14 are fine
.NET 5 all idle for now 1 in Kubernetes (Linux) the others as Windows services
Sharing an SQL Server

2

08:06:22 W 52 Server some-server_ef5bc0c1-d2ae-4e1a-83a8-c2eafeba1b50:11148:5a94ab8a was considered dead by other servers, restarting…
08:06:22 W 12 Server some-server_ef5bc0c1-d2ae-4e1a-83a8-c2eafeba1b50:11148:5a94ab8a stopped non-gracefully due to ServerWatchdog, ServerJobCancellationWatcher, ExpirationManager, CountersAggregator, Worker, DelayedJobScheduler, RecurringJobScheduler. Outstanding work on those dispatchers could be aborted, and there can be delays in background processing. This server instance will be incorrectly shown as active for a while. To avoid non-graceful shutdowns, investigate what prevents from stopping gracefully and add CancellationToken support for those methods.

HeartbeatInterval: TimeSpan.FromSeconds(15),
SchedulePollingInterval: TimeSpan.FromSeconds(15),
ServerCheckInterval: TimeSpan.FromMinutes(5),
ServerTimeout: TimeSpan.FromMinutes(5),
ShutdownTimeout: TimeSpan.FromSeconds(15),
SQL Server CommandBatchMaxTimeout: TimeSpan.FromMinutes(5),
SQL Server CommandTimeout: TimeSpan.FromSeconds(30),
SQL Server DisableGlobalLocks: true,
SQL Server QueuePollInterval: TimeSpan.Zero,
SQL Server SlidingInvisibilityTimeout: TimeSpan.FromMinutes(300),
SQL Server TransactionTimeout: TimeSpan.FromSeconds(30),
SQL Server UseRecommendedIsolationLevel: true

Tried changing the values above around, no luck so far
Any help please?