Fusion Drive S.M.A.R.T. Error when Installing Big Sur, but not in Disk Utility

I was trying to upgrade my 2017 iMac with a 2 TB Fusion Drive to Big Sur today. I get the following error from the Big Sur installer: "This disk has S.M.A.R.T. errors. This disk has a hardware problem that can't be repaired. Back up as much of the data as possible and replace the disk."

When I run Disk Utility, the drive shows no errors. Further, when I "Get Info" on the drive in Disk Utility, it says: "S.M.A.R.T. Status: Not Supported".

I'm a bit confused by the seemingly contradictory messages. I've spent a fair bit of time searching and that has only left me a bit more confused - with some articles suggesting that iMacs from the past few years do not monitor S.M.A.R.T. features (hence, the "Not Supported" message). As such, is my hard drive really about to fail or is this some type of system error? If the latter, any way to fix it? Or to double-check if there really is a problem?

Thanks in advance.