Noisy Ironwolf drives in PR4100

I have two Seagate Ironwolf 6TB drives installed in a PR4100. It’s been running since May 2020. Around July the drives are noticeable noisier from May. I hear random chunking/clicking sounds even when the PR4100 shows it’s in Standby mode. The noise during Standby is not constant. It’s dead quiet right now, for example.

When the NAS is being accessed, it’s obvious–not something I’d keep next to my TV but in a different room. I just started up Plex on my phone to stream some music and I heard the drives spin up and now I can hear the drives being accessed. I stopped streaming but I can still hear the drives working and noone else is on the network.

The noise isn’t the real issue, but if the noise is a symptom of a problem to come, I want to head it off before a failure. The drives are showing as “Healthy” when I log in to the web interface, but that’s as far as I know to check. The system seems to be performing normally. I know there’s a “SeaTool” from Seagate but I don’t know how to run that on this NAS.

Is this something I need to worry about/follow-up with Seagate, or are these drives just noisy? I was thinking about undocking one of the drives to isolate the noise to one or both drives.