Turn on a multi-functional pressure cooker (such as Instant Pot) and select Saute function. Let warm up and add butter and olive oil. Add onion, celery, bay leaves, and thyme. Cook, stirring occasionally, until onion starts to turn translucent, about 5 minutes.

Add carrots, bacon, garlic, salt, and pepper. Cook until fragrant, about 1 minute. Add broth and bring to a simmer. Stir in split peas. Close and lock the lid; set release knob to Sealing position.

Select Manual/Pressure Cook setting according to manufacturer's instructions; set timer for 18 minutes. Allow 10 to 15 minutes for pressure to build.

Release pressure using the natural-release method according to manufacturer's instructions, about 15 minutes. Turn steam release knob to Venting and use quick-release function for the remaining pressure. Carefully open lid. Remove bay leaves. Taste and adjust seasonings as desired.