flushSync set state wrapped in #if that should be releaved, breaks reactivity temporarily

[raythurnvoid]

Describe the bug

When updating a $state that is used to interpolate the value inside an if block using flushSync, and that same if block should be revealed by another $state, the reactivity temporarily breaks until the if becomes falsy again.

Regression introduced in 5.28.3 version.
This is the culprit commit: #15895

Reproduction

https://svelte.dev/playground/a89aaf76146c4571a996d7cd02e39d2f?version=5.33.14

System Info

(Svelte Playground - Edge 136.0.3240.92)

Severity

annoyance