According to this answer I should be able to protect a question if it has "at least one answer by a new user aka a user with < 10 rep on the site".

Yet I do not see option to protect appearing in Bee flying between two trains. It currently has an answer by a user with reputation 1.

What am I missing?

@MartinSleziak The question must also be at least one day old.

I see. "Users with at least 15,000 reputation can protect or unprotect any question at least a day old." meta.stackexchange.com/questions/52764/…

Thanks for the quick response!

Hmm, it has three answers by 1-rep users, two of them deleted. I'd better keep an eye on it, it may need protection before it is one day old.

The same faq says that: "The system (via the Community user) will automatically protect a question that's had three answers from low-rep users deleted or 5 answers from low-rep users posted in the past 24 hours."

So perhaps the system does it after 24 hours even if nobody does anything to the question.

Anyway, it is not surprising that questions shown in HNQ which is additionally open to interpretation attracts some answerers from other sites.