My best guess is that the first dealer messed up the update process when upgrading the firmware of the HVAC system.
They are supposed to update both the BMS and FATC together.
(The HVAC system is managed by an ECU known as FATC (Full Auto Temperature Control).)
I am betting they messed up.
If you can get the second dealer to check whether your car needs a FATC upgrade we will find out.
TECHNICAL SERVICE BULLETIN: SERVICE ACTION: BMS/FATC OPERATION LOGIC IMPROVEMENT WHILE BATTERY CHARGING (SA427) - This bulletin provides the procedure to upgrade the Battery Management System (BMS) and Full Auto Temperature Control (FATC) software on some 2016-2017MY Soul (PS EV) vehicles, produced from May 21, 2015 through August 29, 2017, in order to improve air conditioning operation while the battery is charging.
The codes for using Torque Pro can be found by clicking the link in the website icon under my user name on the left.