This was caused by the base page tagging.
Since that the base page is now required for fixing
soft shadows, it would be the first level to be rendered
which, combined with the update throttle, lead to only
the min LOD to be available when the shadow was updated
in viewport.
This was affecting the jittered shadows, animation update
and viewport transform.
The fix is to only request the base page after throttling
the updates and only if there is no other LODs to be
rendered. This mean jittered shadow in viewport might
become affected by the missing base page artifacts, but
this is less noticeable than huge light leaking.
only if
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