Hmm, was about to reboot and see what BIOS temp says, when I clicked reboot, a message saying WIndows updates have been instaled appeared (I hate WIndows 10 doing this).
Anyway, booted into BIOS and CPU temps were as expected.
Booted back into windows and temp now seems to be displaying correctly (see attached)
Whether this was a glitch in your program that a reboot cured or something to do with the windows update that was installing in the background, don't know, probably the win update.
many thanks