(AP) — Frustrating security lines dwindled at U.S. airports on Monday, removing some of the worst bottlenecks as Transportation Safety Administration officers began receiving backpay for working during the government shutdown.

What was a four-hour checkpoint line at Houston’s George Bush Intercontinental Airport turned into a wait of 10 minutes or less on Monday. Wait times pushed beyond two hours at New York’s LaGuardia Airport Monday morning, but that appeared to be an exception, with normal waits at previous trouble spots such as Baltimore-Washington International Airport and Atlanta’s Hartsfield-Jackson International Airport.

After weeks of airport chaos, there was finally optimism for the beleaguered aviation system. Weary travelers hope the overdue paychecks will end the seemingly endless security lines and missed flights that many experienced in recent weeks. It remains unknown how long it will take for wait times to normalize — and how long federal immigration officers will maintain a visible presence in airport terminals — as the busy spring break travel season continues.

TSA workers told union leadership Monday that they received some — but not all — of their back pay, according to Johnny Jones, secretary-treasurer of the TSA union. He said the rest, from a partial paycheck at the start of the shutdown, is expected by next week.

The TSA chapter of the American Federation of Government Employees also raised concerns that some employees reported incorrect backpay amounts, including missing overtime and improper tax withholdings.

The union also said the TSA updated its furlough policy on Sunday, removing guidance that allowed officers to request a furlough if they could not report to work for reasons tied to the shutdown, such as lack of transportation or childcare.

“Working without pay forced more than 500 officers to leave TSA and thousands were forced to call out,” acting TSA Assistant Secretary Lauren Bis said in announcing the delayed payday.

The union agreed with these numbers, but said those who could not afford to report for duty now “have disciplinary actions looming over their heads.”

“Backpay alone does not fix those problems,” the union said.

The DHS shutdown resulted in not only travel delays but also warnings of airport closures as TSA workers missing paychecks stopped going to work. Those workers were just recovering financially since last fall’s extended government shutdown.

President Donald Trump on Friday ordered the Department of Homeland Security to pay TSA officers immediately to ease the lines plaguing airports. The move came after Trump rejected bipartisan congressional efforts to fund the TSA while negotiations continue with Democrats, who have refused to approve more funding without restraints on Trump’s immigration enforcement and mass deportation operations. The order left other DHS employees unpaid.

Democrats are demanding better identification for the officers, judicial warrants in some cases and for agents to refrain from conducting raids around schools, churches or other sensitive places. Republicans and the White House have been willing to negotiate on some points, but the sides have yet to reach a final agreement.

On Monday, there were few signs of progress on Capitol Hill, where the Senate held a short session without considering the House bill and resumed its two-week break. GOP Sen. John Hoeven of North Dakota said afterward that Senate Republicans are talking with Democrats and also the House as they try to find a way to funding DHS.

The union again urged Congress to approve funding for the entire Department of Homeland Security. “To say we are utterly disgusted and disappointed with our elected officials is an understatement. Congress must come back to Washington, fix this crisis, and stop putting politics over people and vacation over values,” the union said.

Press secretary Karoline Leavitt said Monday that Trump has offered to host an Easter Dinner at the White House for members of Congress who return to resolve the impasse. As for the Democrats’ demands, she said that despite a change in leadership at DHS with Markwayne Mullin replacing Kristi Noem, “There has not been a change in policy.”