ReadyNAS RN314 with 8 TB disks reading false temperatures and shutting down

Hello,

We have recently replaced the 1 TB disks in our ReadyNAS unit with 8 TB Seagate disks and the upgrade went smoothly. However, since the upgrade, we're getting random automatic shutdowns of the whole unit. The logs show that this was because temperatures of different disks reach a critical point of 61 C.

I already set the fans to be "Balanced" and to even the maximal setting to "Cool". What is strange is that in the web interface, the SATA SMART information does not consistently show the disk temperatures. Sometimes the temperatures are blank and if I hover over the disk it shows "-1 C". Is there a known compatibility problem reading the SMART fields from these disks? Does anyone have a solution to this other than the unsafe option to uncheck the shutdown if the disks get too hot?

Thanks.

Cengiz