Further, Democrats are all but certain to initiate investigative work on the so-called Mar-a-Lago group, an informal set of advisers that the Trump administration has turned to on veterans issues, now the subject of a lawsuit.

Personnel changes in Congress also are expected to have an effect on attention to the issue. The expected incoming chairman of the House veterans committee, Representative Mark Takano of California, is generally viewed as more liberal — with an aggressive oversight agenda.

“We welcome congressional oversight,” said Curt Cashour, a spokesman for the department. “We also appreciate Congress’ work and cooperation in helping President Trump achieve more substantive reforms at V.A. in the last two years than at any other time in decades.”

Significant changes to laws governing veterans issues have been made under the Trump administration, something that has often been obscured by the politically charged turmoil in leadership at the Department of Veterans Affairs and by Mr. Trump’s occasional attacks on prominent veterans, to the frustration of congressional Republicans and some administration officials.

A previous secretary held over from the Obama administration was fired via Twitter after political brawls, and Mr. Trump’s first proposed replacement, Dr. Ronny L. Jackson, a White House doctor, never made it to the Senate confirmation process after members of both parties attacked his professional conduct.

Putting the new laws into effect has proved bumpy. For instance, under changes made to the G.I. Bill in 2017, veterans’ housing allowances were recalculated to be based on where veterans take classes, rather than their school’s main campus, which had resulted in some veterans being overcompensated for housing, while others were shortchanged.

The department asked colleges, universities and landlords to hold off on their requests for tuition and rent while it prepared its information technology systems for the change to meet an Aug. 1 deadline. When they realized they were running out of time, officials signaled schools to submit their claims, which led to a swamping of the already underwater systems. That held up payments to thousands of schools and landlords.