I just installed the V2 to V3 HE and firmware.
After the upgrade and upload of the new firmware, when I set the new HE to 250, for example, the printer will heat to 247 and stay there. I can get it to heat to 250 by setting it to 253! A very similar issue with the bed. It also used to heat up fairly quickly, now very slowly and if I set it to 100, it will stop at around 97. I can get it to 100 if I set it to 103.
The issue happens whether I dial the temp manually on the printer or use Matter Control via USB, or any other print program.