Place the potatoes, andouille sausage, onion, garlic, 1 tbsp Old Bay, and 4 tbsp butter in the liner of the Instant Pot. Put the corn on the cob on top and pour chicken broth over everything.
Turn the Instant Pot to HIGH and cook for 5 minutes. When the time is up, perform a Quick Release.
Add the shrimp into the pot, replace the lid, and cook on HIGH for another minute. When the time is up, perform another Quick Release.
Melt the remaining 4 tbsp of butter and mix it with 1 tsp Old Bay. Drizzle the seasoned butter over everything in the pot. Garnish with lemon wedges and parsley. Serve and enjoy!