The culprit: `resolveElement` doesn't pass a Window to `element.isStale`: https://searchfox.org/mozilla-central/rev/25d5a4443a7e13cfa58eff38f1faa5e69f0b170f/layout/base/tests/marionette/selection.py#11
Bug 1671370 Comment 7 Edit History
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The culprit: `resolveElement` doesn't pass a Window to `element.isStale`: https://searchfox.org/mozilla-central/rev/86d73c5d10674d964de467e157402f160d1d2945/testing/marionette/element.js#806