Bought the vehicle used with approximately 6,000 miles on it. Within the following weeks noticed the shifting issue. Happens regularly. Usual problem is when accelerating from a stop or very slow depressing the throttle has little or no effect. Depressing it further usually results in a stall or sudden, hard acceleration. Almost impossible to increase speed smoothly.

Update from Mar 20, 2022: Vehicle just began having the fuel pump issue which may be the base cause of this complaint. When engine stumbles or stalls the driver's reaction is to use more throttle which may cause the transmission to shift hard.