A late-night Uber ride from Toronto’s Pearson Airport into the city usually guarantees a good fare for the driver.

But not for Sachindeep Singh on the evening of Sept. 19.

A few miles into the ride, his Uber app stopped working.

Mr. Singh’s work permit had expired at midnight and, like Canada, Uber was putting him on notice.

Mr. Singh, 23, arrived in Canada as an international student in 2019. His immigration status permitted him to work and offered a path to permanent residence, an approach labeled “study-work-stay” on the Canadian government’s immigration website.

But after inviting millions of newcomers to Canada in recent years to help lift the economy, the government has reversed course amid growing concerns that immigrants are contributing to the country’s deepening challenges around housing, health care and other issues.

A series of measures unveiled this year, focused on Canada’s vast temporary residence program, has imposed barriers that have left hundreds of thousands of migrants like Mr. Singh in legal limbo.