You seem to have been affected by a bug that caused DM notifications to be muted and break if you used the MuteNewGuild plugin.
If you haven't received any notifications for private messages, this is why. This issue is now fixed, so they should work again. Please verify, and in case they are still broken, ask for help in the Vencord support channel!
We're very sorry for any inconvenience caused by this issue :(