My printer was working as it should. During a recent print using PLA with a nozzle temp of 215, bed temp 80. Shortly after the first layer was printed the nozzle temp drops to 190 for no obvious reason. The only firmware change I made recently was re-calibrating the e-steps. Even if I go into the display and re-enter the temp to 215, the temp never goes back up. The display will read 190/215. I thought it might be the firmware got corrupt. I reinstalled the firmware and that did not fix the issue. I checked all my connections and do not see anything wrong. Everything is plugged in. I made sure that I did not inadvertently set something wrong in Slic3r, all was ok. I DO have a part cooling fan but that is turned off.

Can anyone tell me why this is happening?
Thank you for your time.
Bill