Transmission not working properly

Good afternoon,

Did you check the fluid level? Make sure it is at the proper level.

https://www.2carpros.com/articles/automatic-transmission-problems

I would also consider changing the fluid and filter. The filter may be clogged.

https://www.2carpros.com/articles/how-to-service-an-automatic-transmission

Beyond that, it is internal such as the front pump or torque converter.

Roy