EL PASO, Texas (AP) — Pandemic-related asylum restrictions that expelled migrants millions of times have ended in a shift that threatens to put a historic strain on the nation’s beleaguered immigration system. The change came early Friday after migrants raced to enter the United States before the new restrictions set in. Meanwhile, the administration was dealt a potentially serious legal setback when a federal judge temporarily blocked its attempt to release migrants more quickly when Border Patrol holding stations are full. Misinformation and confusion buffeted migrants as they paced the border at the Rio Grande, often unsure of where to go or what to do next.