Do your DIMM have thermal sensor? Also not all servers REG ECC DIMM (RDIMM) have it. Example server's REG ECC DIMM Samsung M393B5170GB0-CK0 (read specification's and THAIPHOON BURNER Super Blaster report)
is have it and HWiNFO64 show DIMM temperature, but desktop DIMM's Kingston HyperX Genesis KHX1600C9D3K4/16GX don't have it - in to specification me can read string Module Temperature Sensor: Not Supported
(also in to THAIPHOON BURNER Super Blaster report).