Sorry for the issues you are having.
Are you using Mac/Windows?
Have you tried a different USB cable?
Are you using a USB hub? If so, please try a direct connection.
You can also try deleting the H90 from H90 Control and adding the device again.
In the future, please post any H90 or H90 Control issues in our stompbox forum: https://www.eventideaudio.com/forums/forum/products/stompboxes/