Problem Statement:

During the migration from Confluence Data Center/Server to Cloud, or when copy-pasting content into the Fabric editor, alignment attributes (such as ac:align="left" and ac:layout="align-start") are automatically injected into image storage formats. However, certain macros—specifically the Excerpt macro—do not support these alignment attributes for media.

This lack of support causes visual regressions, such as the clipping of image borders on the left side. Since the Excerpt macro currently defaults to a centered-style behavior for media that lacks alignment data, the presence of these "unsupported" attributes causes rendering errors.

Suggestion:

Update the Confluence conversion and editor logic to automatically sanitize media attributes within the Excerpt macro to remove unsupported elements like image "left" alignment