Small update: If we publish the app workspace as app and hand users a build permission via the published app, the RLS works fine with Analyze in Excel. But, of course, getting this to work in the app workspace would be better, because I can set a more granular level, who gets a build permission instead of all published app members.
I am having the same problem, but do not see a way to apply 'Build' permission only at the app level. I remember seeing App(Build) for users on the dataset in the past, but maybe has it changed?
Now, when I change the App to allow build permission for a specific user, it actually adds the Build permission for them to the underlying dataset (thereby disabling RLS)... I can't seem to get it to only apply to the App. Any help is appreciated!