Combine brown sugar, mustard, balsamic vinegar & honey in a small bowl. Whisk to combine & set aside.
Place ham on a large piece of foil & make slices halfway through the ham.
Spread the brown sugar mixture over the ham to coat.
Close the foil around the ham to completely cover.
Place the ham on the trivet in the cooker pot.
Add 1-1/2 cups of water to the pot.
Close the lid & cook on manual for 18 minutes.
Natural release for 10 minutes, then quick release.
Remove the ham & let rest in the foil for 5 minutes.
Remove the ham from the foil & transfer to the serving platter.
Pour out the water from the pot & pour the liquid from the foil into the pot.
Add pineapple juice, remaining water & cornstarch to the pot.
Cook on sautee, whisking frequently until mixture has thickened to your desired consistency.
Drizzle over the top of the ham prior to serving.