Combine all but the last 3 ingredients into the instant pot - chicken, enchilada sauces, cream of chicken, diced tomatoes, green chiles, taco seasoning, milk, black beans, & corn
Cook on manual for 20 minutes, with quick release
Shred chicken
Immediately stir in sour cream and cheddar cheese while soup is still piping hot, if it's cooled set instant pot to saute and stir in sour cream and cheese
Top with tortilla strips, more sour cream and shredded cheese and enjoy!