With the Instant Pot set to "Saute" and the liner in place, brown the ground beef and Italian sausage for 5 minutes. Add the onion; cook, stirring as needed, for 3 minutes. Add the garlic; cook for an additional 2 minutes, stirring as needed.
To deglaze the bottom of the liner, add about 1 cup of the beef broth to the meat mixture. With a non-metal spoon or spatula, scrape the bottom of the liner to loosen any bits that may have stuck while cooking. This will help to avoid a "burn" notice on the Instant Pot. Press "Cancel" to turn off the Instant Pot.
Working in batches, break the spaghetti noodles in half. Arrange noodles in layers in a criss-cross fashion over the meet mixture. For best results, use 6 or more layers. This will help insure that the noodles are not too crowded and will allow the liquids to move freely to avoid clumped noodles.
Pour the tomatoes and the remaining beef broth over the noodles. Sprinkle the spices over the tomatoes.
Lock lid in place. Put the release valve in the "Sealing" position. Press the manual button and set pot for 7 minutes on high. After a few seconds the pot will switch to "ON" while it comes to pressure. This will take approximately 10-15 minutes. When the Instant Pot reaches the appropriate pressure, a single 'beep' will sound and the pot will begin its countdown. The minutes-to-cook will display in the panel.
At the end of the cooking cycle, there will be several beeps and the pot will stop. The "Keep Warm" function will activate, unless you have canceled it. Perform a "Manual Release" by moving the pressure valve into the "Venting" position. The steam will release forcefully for a minute or two. Keep all body parts away from the steam.
Once the steam has completely released, the locking mechanism will release. Carefully open the lid. With a large, long-handled spoon, stir the pot contents. Be sure to stir from the bottom of the pot, lifting the contents to the surface while stirring.