Your system has quite a few thermal sensors though out the system. The best way to see what's going on is to review them via a good App that can show you more graphically each of the sensors. There are a few Apps which will do that I found [https://www.tunabellysoftware.com/tgpro/|TG Pro] is one of the best! Download the trial version and post a snapshot of the main window's display of the sensors here so we can see things. Keep in mind the list will exceed the screen so you'll need to scroll the list down to get the bottom ones in a second snapshot.
You may want to run the systems onboard diagnostics as well to see if something shows up there. Restart the system and press the ***D*** or ***Option*** (***⌥***) and ***D*** keys as outlined here [https://support.apple.com/en-us/102550|Use Apple Diagnostics to test your Mac]
Let us know what you discover!