Rpi 4 with Myserver 6 will not boot consistently

I have been having some network issues, and during this I have replaced my router and WiFi AP, the Myserver Pi4 is ethernet attached and has a fixed ip handed out as a DHCP lease from the router. During all of the changeover Myserver became unresponsive. It is headless so I connected a keyboard mouse and monitor and the screen wouldn't come up after tapping keys or moving the mouse. So I powered down the RP because it seemed it was locked up. 

It started the boot process but hung up here. See attached JPG. It seems to be that it's not seeing one of the partitions on the USB drive. Ive had this happen a couple of other times when rebooting the RPI. The fix has been to remove the usb drive and place it in another usb port, type exit at the shell and then it boots normally, I then shutdown the rpi from the keyboard and return the usb drive to the original slot and then power it back up. It boots normally after this.
https://drive.google.com/file/d/1ETFHwczQN9AMJoQTugqpfIb5dQmIJACJ/view?usp=drive_link

Hi Mark,
that sounds like the USB got corrupted. Most common (by far) is by power cycling the myServer controller (big no-no).
This typically corrupts only the boot sector and not the myServer Application space. To fix, create a second myServer Master Image, boot from that, and insert the myServer original USB post boot and transfer your custom db, and wwwroot custom folder(s) to the new boot drive. Shutdown, pull the Old usb and reboot.
If you keep a backup of your files on a second PC (highly recommended), just network the new USB and transfer the files from there (typically easier since the two USBs will have same device ID (same Master Image) and it can be difficult to find the second USB).