So is this a Windows Calculator bug or is just ignorance about metric ton?

"Monty" escreveu na mensagem
...

The description below is from Encyclopedia Britannica and reflects
what I learnt in school about 70 years ago.

" Ton, unit of weight in the avoirdupois system equal to 2,000 pounds
(907.18 kg) in the United States (the short ton) and 2,240 pounds
(1,016.05 kg) in Britain (the long ton). The metric ton used in
most other countries is 1,000 kg, equivalent to 2,204.6 pounds
avoirdupois.

Ton came to mean any large weight, until it was standardized at 20
hundredweight although the total weight could be 2,000, 2,160,
2,240, or 2,400 pounds (from 907.18 to 1088.62 kg) depending on
whether the corresponding hundredweight contained 100, 108, 112, or
120 pounds."

I am not aware of any "ton" being defined as 2,200lb.