Had the same thing happen today on the same side of my 2016 St. After using penetrating oil and working it manually, it has gotten better. If you actually fixed yours what did you do? New cable?
Yeah fitted a new cable Sean, £58 from ford, but omg what a nightmare job to do on axle stands in the street! Everywhere I rang couldn’t do it for two weeks but I needed the car to go away in… so bit the bullet and did it myself, pretty pleased with myself for doing it, but it was a fiddly job to do!