If your beans don't seem cooked enough you can always secure the lid back on the Instant Pot and cook the beans for a few more minutes, as long as there is still liquid in the pot. For this reason, it's often better to error on the side of slightly undercooking the beans, because you can always add more cooking time. Make sure to stir the beans first, so that the beans on the top are mixed back into the water before they're cooked again.
Some brands of beans (especially higher quality, fresher beans) will cook faster than bags of inexpensive grocery store beans.
You can make this recipe using a full pound of dried beans. For a full pound of beans, I add 6 cups of water.
When cooking beans (and grains) it's recommended that the Instant Pot is never filled more than half full. Beans and grains need room to expand as they cook.
This recipe was tested in a 6-quart Instant Pot.