USB boot / Wifi / BT issue RPi 3b+

[RedRyder]

Hello-

I have found a puzzling USB boot issue. System is a Raspberry Pi 3b+ OpenPlotter 1.2.0

First - my setup works fine if I boot from an SD card.


Next, I did the following:

• Copied the SD card to a USB drive (it's using an mSata3-USB3 adapter, the x850)
  
• Edited /boot/cmdline.txt to change the boot location
  
• Edited /etc/fstab entries for the / and /boot partitions
  

Findings:

• Strangely, boot fails part-way through when booting with just the USB drive connected. It starts, gets part way, and stops.
  

• I create a new FAT32-formatted SD card with only bootcode.bin on it, insert into Pi
  
• Boot succeeds and I get to the desktop. 
  

• These issues are seen:
  
• Bluetooth unavailable
  
• Wifi unavailable (the country is still set in wpa_supplicant.conf)
  
• Sound/audio is unavailable
  
• Attached USB accessories cannot be used. This includes: keyboard, mouse, CAN-USB device
  

Please help! I have not seen these same issues with a "stock" Raspbian installation.