Add bacon to Instant Pot. Select sauté and adjust to normal. Cook and stir until bacon is cooked through but not crisp for about 8 minutes. Remove bacon to a paper towel-lined plate; refrigerate.
Remove all but 1 tablespoon of the bacon grease from the pot. Add onions and garlic to drippings in the pot. Cook and stir for 5 minutes until just tender. Press cancel.
Add brown sugar, apple cider, vinegar, thyme, cinnamon, and cayenne. Stir to combine.
Secure the lid on the pot. Open the pressure-release valve. Select slow cook and adjust to less. Cook for 6 to 7 hours. Press cancel.
Add cooked bacon to pot. Select sauté and adjust to less.
Cook jam until most of the liquid has been evaporated for 5 to 10 minutes. Press cancel.
Cool and refrigerate for up to 1 week. (Jam can also be frozen.)