Are SMART warnings reliable? ( TTP 10.1.2 - OSX 10.14.2 )

I am getting a SMART Warning from TTP 10.1.2 Protection. TTP app reports an incompatibility with Mojave 10.14.2.

Does this mean the warning is unreliable?

The drive is a brand new LaCie 6Tb TB2 HDD external. I have copied 5.2Tb of DATA over the last 2/3 days. Drive is directly connected via TB2 to Macbook Pro and a display daisy chained; TB2 to mini DP, from the drive.

Extended Health & Command Timeout are shown midway between pass & fail, if the SMART test is run in the app.

Disk Utility reports no problems.

Is there any action I can take?

Should I return the drive?

thanks