Overview: By default, the position-try fallbacks are "sticky", i.e. an option is used until it's invalidated either because a) it no longer fits b) there's a style recalculation that triggers re-evaluation of position-try options This behavior is intended to provide some visual stability for the user. Affected WPT Tests: * http://wpt.live/css/css-anchor-position/last-successful-basic.html * http://wpt.live/css/css-anchor-position/last-successful-change-fallbacks.html * http://wpt.live/css/css-anchor-position/last-successful-change-try-rule.html * http://wpt.live/css/css-anchor-position/last-successful-iframe.html * http://wpt.live/css/css-anchor-position/last-successful-intermediate-ignored.html Specification Notes: See https://www.w3.org/TR/css-anchor-position/#fallback It's possible that we might find places where the spec should be adjusted, since we are the second implementation and what makes sense to do here might not be entirely obvious. In these cases we should implement what makes sense to us and bring the issue to the CSSWG for discussion.