Most larger leagues are now in the beginning of their 30 day suspensions, the Federation has followed suit due to the Coronavirus.
US Open Cup Commish. Paul Marstaller informed "The health and safety of players, coaches, staff and fans is our main priority. Given the unique nature of the competition, which encompasses clubs from multiple leagues that have suspended their seasons, we are taking this action and will look to determine future dates to allow the 2020 Lamar Hunt US Open Cup to be played."
They came to this decision following the MLS, USL & NISA pro leagues to suspened play from 2-4 weeks, the NPSL did similarly partially suspend league play until April. 4. Locally the CSL,CJSL, LISFL, LIJSL etc have also shut down.
The first 3 rounds of the games were set for March 24-25. Apr. 7-9 & 21-23.