It could be best to check the temperature around the car to see if the door mechanisms are being impacted by snow or ice. To check if it helps reset anything, try locking and unlocking the doors with the fob as well.
The 6-speed manual transmission in the Dodge Charger R/T is made by Tremec. They’re well-known for their high-performance transmissions in various muscle cars, including the Charger. Hope that helps!
I totally get the frustration with early issues, but keep in mind, first-year cars often have bugs. My Hornet had a fuel pump issue, but after a fix, it’s been running great. Hang in there, Dodge will improve it..
The axleback for the Wrangler 2L Hurricane engine likely won’t fit the Hornet GT without modifications due to design differences like the rear axle and engine placement. You might want to look into Hornet-specific exhaust options from MagnaFlow or HornetMadness instead.