Slice and rinse bell peppers. Set aside.
Add chipotle peppers, adobo sauce, cream cheese, 1/8 cup cilantro, and 1 tsp lime juice into a small food processor or blender. Pulse until a smooth puree has formed.
Add chicken thighs, fajita seasoning, tomatoes and green chilis, chicken broth, brown sugar, and chipotle puree into your Instant Pot. Stir to ensure that chicken is completely coated.
Seal Instant Pot and set to manual/pressure cook for 10 minutes (if using thawed chicken) or 15 minutes (if using frozen chicken). Let naturally release for 5 minutes before flipping the switch to quick release the rest of the pressure.
Remove chicken thighs to a bowl and shred.
Add bell pepper slices to the remaining liquid left in the Instant Pot and set to manual/pressure cook for 2 minutes. Quick release immediately.
Return shredded chicken to the Instant Pot and stir in the remaining 1/8 cup cilantro and 1 tsp lime juice. Serve on tortillas with cheese, guacamole, creamy jalapeno sauce, and a hot sauce of your choosing.