There's a literal Canada post strike going on for weeks now. Squirrel wouldn't know, all he reads it's melt your mind misinformation and thinks that is news.
Be fair, he mentions that strike in his comment.
I'm just saying that that's not the issue here, as there is no such strike in UK, but that I've noticed the mail becomes hopelessly unreliable at this time of year, pretty much every year, and my theory is that it's because this is the time when they take on lots of untrained temporary staff to cope with the Christmas rush, and those temporary workers seem to be prone to 'lose' stuff.