System Agent Core temp?

Hello, I don't know if this is a known bug from istat or just something wrong with my MacBook Pro Retina (2015). I've been using istat to measure the temps and I noticed that the system agent core sometimes jumps from a normal temp (around cpu temps) and 0 degrees. It shows 0 degrees then jump to its normal temp for a while and then 0 degrees. Like if it was 0 degrees while on idle. It's the only sensor that I noticed so far acting like this. I couldn't find anything on the web about this subject in particular, so I'm a bit worry about what it might be even thought doesn't seems to affect the system performance in any way. Thank you!

 

Yes. I was wondering that either that or the sensor would be acting faulty in some way which seems odd.