FYI for anyone unaware: blocking users is a core Lemmy feature and blocking with an app should block inside Lemmy itself; meaning if you switch apps or log in from the web, your block list remains intact.
Instance blocking is not a core Lemmy feature (yet) and so if it’s available in your app, be aware that your app is what does the blocking. Meaning if you switch apps or log in from the web that block won’t be there.