Transmission When coming to a stop, it is very hard downshifting?

Let's run the codes because it seems like you have an input shaft speed sensor (turbine) that is not working, or the value of the sensor has degraded. Also, can I ask if the engine power is normal? If not and the engine is down on power, you could have a partially clogged catalytic converter.

Here is a guide to help us:

https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing

This is the location of the turbine sensor in case you need it, also has the transmission been serviced lately. I would do this as well.

Here is a guide to help:

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

Transmission Fluid Type

5R55S .................... Motorcraft MERCON V ATF XT-5-QM

6R60 .................... Motorcraft MERCON SP ATF XT-6QSP

Capacities

Transmission Fluid

5R55S .................... 12.4 Quarts (11.7L)

6R60 .................... 11.2 Quarts (106L)

I have included the transmission service procedure for your car as well.

This guide can help as well:

https://www.2carpros.com/articles/how-to-check-and-add-transmission-fluid

Check out the images (below). Please let us know what happens.