Set your Instant Pot to Sauté mode on high. Add avocado oil and let it heat for 1-2 minutes.
Pat the beef cubes dry with paper towels and season generously with salt and pepper. Working in batches to avoid crowding, sear the beef cubes on all sides until deeply browned, about 2-3 minutes per batch. Remove and set aside.
Add the diced onion and celery to the pot and sauté for 3-4 minutes until softened, scraping up any browned bits from the bottom.
Add the minced garlic and cook for 30 seconds until fragrant.
Stir in the chili powder, cumin, smoked paprika, oregano, and cayenne pepper. Toast the spices for about 1 minute, stirring constantly.
Add the tomato paste and stir to coat the vegetables, cooking for another minute.
Pour in the diced tomatoes and beef bone broth. Use a wooden spoon to scrape any remaining browned bits from the bottom of the pot.
Return the seared beef and any accumulated juices to the pot. Stir to combine everything.
Cancel the Sauté mode. Secure the Instant Pot lid and set the valve to Sealing. Cook on High Pressure for 25 minutes.
When the timer goes off, let the pressure release naturally for 10 minutes, then carefully quick-release any remaining pressure.
Open the lid and stir in the diced zucchini. Let it sit for 5 minutes to soften in the residual heat, or turn on Sauté mode for 2-3 minutes if you prefer it more tender.
Taste and adjust seasoning with additional salt and pepper if needed. Serve hot in bowls.