Construction on the REX-designed performing arts center at Ground Zero could be delayed if the federal government decides to revoke millions in funding.

After 9/11, the U.S. Department of Housing and Urban Development (HUD) gave nearly $3 billion in funds to the Lower Manhattan Development Corporation (LMDC), the public-benefit program in charge of the area’s regeneration. The LMDC has $150 million of that grant money left to spend, and the group planned to use around $100 million of those funds on the luminous Ronald O. Perelman Performing Arts Center at the World Trade Center (the Perelman Center, for short).

That plan, though, was called into question at a recent LMDC board meeting. REX’s project would be built on Port Authority land, but the agency says the LMDC owes it money for the work it did to prepare below-grade land for construction. Both parties agree on the existence of the debt, but not the amount: the Port Authority says it’s owed $67 million, while the LMDC claims it owes only $45 million. These issues could leave Perelman Center construction at an impasse, but Crain’s reports the two parties are working towards a compromise by the end of June.

In HUD’s eyes, the LMDC may have done too good a job bringing the World Trade Center area back to life. The neighborhood—with new and new-ish buildings by Calatrava, SOM, Fumihiko Maki, and (soon) BIG—has bounded back in the 16 years since the 9/11 attacks. Given its remarkable resurgence, state and local officials say the LMDC completed its fundamental task, so HUD may want its money back.

Though restaurants are extending the neighborhood activity past 5 o’clock, the Perelman Center boosters say the area needs a performing arts center to fully cultivate a 24/7 neighborhood. In addition to shows, the first floor would be home to a cafe and restaurant with extended hours that would, its architect said, anchor the neighborhood by drawing people in even in the absence of scheduled performances.