SYDNEY, Australia — During her second week waitressing at a barbecue restaurant in Sydney, a customer asked Yating Yang if she was Chinese. “No, I’m Taiwanese,” she said.

Her boss, who was from mainland China, never gave her another shift.

Man-Tzu Tuan said her loyalty test came even sooner: on her first day at a hot pot restaurant in a comfortable Sydney suburb. “Is Taiwan part of China?” her manager asked in Mandarin over a walkie talkie. “No, definitely not,” she said.

A half-hour later, she was fired.

China’s assertiveness has already set off alarms in Australia, with officials warning that Beijing has been meddling in Australian politics more than the public realizes. But the experiences of Ms. Yang and Ms. Tuan — along with many others — reveal how Chinese nationalism is also affecting private enterprise and, in some cases, leading to accusations of discrimination.

Australia’s fair work laws make clear that an employer cannot discriminate against an employee or prospective employee because of the person’s “political opinion, national extraction or social origin.” But experts and Taiwanese workers say that is exactly what many Chinese business owners are doing, with few repercussions.