UPDATE: Twitter DM's have been back up for a while.. For now. Will look into alternate solutions, soon...
Unfortunately Twitter alerts are down again. Twitter seems problematic. I'm considering moving direct messaging elsewhere - gab.com for instance. Additionally I'll be looking into other channels for notifications. If you happen to have any suggestions, please let me know.
For now, I'm in discussion with Twitter in the hope to resolve the problems they keep creating for me... :)