I agree this is likely an operator and/or tire issue. The fact the tires are only 1 year old doesn’t mean much.
The tire compound could be responsible.
Some year ago I had a set of Kelly tires on my other Lincoln. Even with 90% tread, on a damp road surface that car would spin the rear tires and on occasion even fishtail when accelerating from a stop. It would even do this without depressing the accelerator pedal; simply removing my foot from the brake pedal would cause it.
Many times I had to hold the speed down to 55 MPH on a 70 or 75 posted damp (no water pooling) turnpike due to those tires because the car would skate all over the place. Even then it was often a 2 hands on the wheel and don’t relax for a second situation.
Those were the worst tires I’ve ever seen in my life and they were barely tolerable on dry pavement, much less wet.