I've seen this question asked in a few places but they all seem to be saying "don't put the modal or the backdrop in a parent that has a position property set" but my modal and backdrop are both under the body element with no other parent, here's a screenshot of the element stack:
when I observe the modal backdrop it has a z-index: 1040 and the ngb-modal-window has z-index: 50. When i change those numbers so that the window has a higher z-index than the backdrop, the problem is fixed, but why is it doing that to begin with?
I've also looked through our app css and we're not overriding any of the css rules. Is it a versioning issue? package.json says "@ng-bootstrap/ng-bootstrap": "^3.3.0",