I encountered the same "issue" (especially during an upgrade from Camel 2 to Camel 4.4). After analysis, it turns out that the observed behavior is related to the implementation of Camel's HealthCheck (https://camel.apache.org/manual/health-check.html). A health check exists for routes consuming via SFTP. I couldn't determine exactly how this health check is performed, but I concluded that if a connection is established, the health check will be OK, and there will no longer be any warnings in the console. The status will remain DOWN or in warning as long as no explicit connection is made.

Therefore, I added the 'initialDelay' option to force polling from the first second of the route's creation and then continue polling at a specific frequency (cron or fixed delay). This resolved the health check issue, and my app is UP right from startup.

https://camel.apache.org/components/4.8.x/sftp-component.html