Why did Islam makhachev pull out?

Makhachev was scheduled to face Alexander Hernandez on April 18, 2020 at UFC 249. However, Makhachev was removed from the card due to travel restrictions related to the COVID-19 pandemic and he was replaced by Omar Morales. Makhachev was expected to face Rafael dos Anjos on October 24, 2020 at UFC 254.