Hi  – so the ratio of bones to liquid should be 2-3 pounds (~1-1.3kg) of bones to 4 quarts of filtered water (16 US cups / ~3.8 liters). 

You didn’t mention how much liquid you used but I don’t think an Instant Pot can hold more liquid than that right?

And when using a pressure cooker like an Instant Pot, it’s not necessary to use apple cider vinegar – although I don’t believe it would affect your gastritis if you did since such a small amount is used. It’s simply to help extract the minerals from the bones better.

Broth/stock should be liquid when hot but how you can tell if you extracted enough gelatin is by putting it in the refrigerator. If it forms a gel when cold, it’s a successful attempt!

Let us know.