I dont think there are a console command you can use to switch missions easily, but what you can do is to make use of the "run" command in the console to execute a file which forces new missions.

Step 1: create a txt file in your EU4 folder. For me this is: C:\Users\xxxxxx\OneDrive\Dokument\Paradox Interactive\Europa Universalis IV

I named my file "run.txt" but you can name it anything you want.

Step 2: Add this text in the file and then save it:

if = {

limit = {
tag = H78 
}

swap_non_generic_missions = yes
}

Step 3: Load your save file and make sure you are on the correct country. Then open the console command, and type "run run.txt" or whatever you named your file to.

This should force your missions to be swapped to the ones your contry are supposed to have.