My students did really well in previous units using functions, but when we got to Unit 7 they were struggling a LOT. They couldn’t keep straight function definition/call, were repeating parameter names in function calls after repeated modeling and non-tech examples (Happy Birthday song takes in a specific name, we don’t sing “Happy Birthday to Name!”, we sing “Happy Birthday to Stacy!”) were creating local variables and assigning them the value of the parameter (which is redundant), or completely breaking down and just staring at the screen (about half my students). The first lesson in Unit 7 using the cake functions completely confused them. I essentially started over with this set of slides and used the Peardeck add on. Hopefully this helps.
If you have any other materials to share please send them my way.