For the past two months, Faye Yang has felt like she's been on a roller coaster. US President Donald Trump's changes to the H-1B visa process are the reason.

Yang, who is Chinese and uses her English name, holds a master's degree from the School of International and Public Affairs at Columbia University. She has been working for about a year at a New York-based culture institution that promotes understanding and relations between China and the US.

And at the end of April, she was lucky enough to win an H-1B visa processing lottery for skilled foreign workers. The lottery is capped at 85,000 visas each year (including 20,000 reserved for master's degree holders). This year, the US Citizenship and Immigration Services (USCIS) received 190,098 H-1B petitions during the filing period.

For most foreign students and workers, the H-1B is a much sought-after non-immigrant visa that allows them to work in the US for up to six years. According to a report by the USCIS, of the H-1B petitions approved in the fiscal year 2017, 75.6 percent of all applicants were born in India, and China was second, representing 9.4 percent of applicants.

Yang recalled that she celebrated winning the lottery with her family. "But just a few weeks after, I received the notice of the Request for Further Evidence (RFE) from immigration authorities," she said. "I heard last year there were many people who received the RFE last year, and many of them had to wait for months for the result. Now I'm really frustrated."

The RFE is a notice that the USICS sends to H-1B winners requesting more information to justify why they deserve the visa. However, during the time it can take to process that requested information — from 10 to 13 months — a worker can't work. Some of those asked for more information could lose their jobs during the waiting process even though their H-1B visas were approved.

"Since last year, we are now getting more unwarranted requests than the past, and also in much bigger numbers," said Fang Peng, a Chinese immigrant lawyer with more than 20 years' experience of representing H-1B applicants. "In 2017, we see much more strict rules on H-1B visas after President Trump took the office. The approval rate of RFEs of last year might be the lowest in the past decade."