@msdropbear42 I hear your frustration, but now I'm a bit confused. Out of the two methods you tried to send DMs to Mastodon accounts, which one worked if any? The Private Message page or the regular Compose page with the Access Control List tailored to send only to a specific account?
Also which Submit button you clicked where nothing happened at all? This could be a local interface/script bug rather than a larger federation issue.