[https://forum.unity.com/threads/are-spriteatlas-variants-not-compatible-with-addressables.1120993/#post-7223158]

From the forum post:

"One issue I did spot is since I have 3 bundles (named differently bundle_HighDef/bundle_Standard/bundle_LowRes) that each have a unique sprite atlas in them (1 master and 2 are variants), but they all 'reference' the same sprite assets in the project folder, if I utilize the Addressables Analysis, under the "Fixable" rules there is an option to find and fix duplicate references. This will list every bundle as having duplicate references (which they technically do) and the fix portion will add all the sprites to each bundle as references to the sprite asset (not the texture2d) and then add a new bundle "duplicateassetsisolation_assets_all" and put all of the texture2d assets for all the sprites in there. In this case this isn't desired behavior."