Why does Alexa speak to me in German?

I speak English. My Amazon account is set to English. My Alexa listens to my English commands and replies in English.

Except for new book notifications.

I saw a pulsing yellow light on the dot. I've memorised all of the various signs and portents the accurs'd device can summon up, so I asked it (in English) what notifications it had for me. It replied, naturally, in German.

I couldn't grab an audio recording in time, and I've no idea which command invokes a repetition. But the Alexa app contains a handy history of every utterance to spew forth from its speaker.

To be clear, my IP address shows that I am in the UK. I have never bough German lager from Amazon. I've never watched Das Boot on Amazon Prime. I haven't even asked Alexa to play the soundtrack to Cabaret!

Whatever. Eine Kline Glitche um Der Matrix.

And then, a few weeks later, it happened again!

Was ist das? Ein großer Haufen Schweinescheiße!

To be even clearer - neither of the authors are German. I stopped learning German when I was 14. My liebe Frau happens to have German A-Level but she swears blind that she only uses it to speak with Hans, our flaschenspüler - and never in front of Alexa.

So what gives?

As far as I can tell, neither of these authors has a new book out. But a German translation of their work has been published. Amazon knows I follow these authors and, because Amazon are Kapitalistische Warzenschweinficker, will gently encourage me to by more of their works. Ordinarily, that might be useful. But as I don't speak the language, it's all a bit pointless.

For some reason, this only seems to happen with German translations. No idea why.

It seems that Amazon's prowess in deep-artificial-learning-neural-technobabble doesn't actually extend to anything useful - like making sure it doesn't read out garbled multilingual sentences.

What a bunch of Kartoffelköpfe!