Have you tried to reboot the miner? Let see if it could fix the issue.

If not then post the API logs here and don't forget to put them on the "insert tag" with a # icon or use pastebin.com and paste the URL here.

The hashboard temp sensor is different so maybe we can see the real temp of the chip under PVT_T0, T1, T2, and maybe one of the chips is overheating that cause this issue?