You can write the RetroPie image directly to the drive and boot from it - assuming your PI has USB boot enabled. If USB boot is not enabled, then you'll need a sdcard to run Raspberry Pi OS and enable it from raspi-config.

@jamiem1976
It appears you are using a recalbox image instead of a retropie image. You might want to ask your question on their forums instead.

Alright, I've tried Ubuntu MATE 18.04 beta 1 extensively and the problem does not occur on Ubuntu at all. Must be a Raspbian issue. Definitely not my hardware. I hate to dig up a month old topic, but it is what it is. A Raspbian issue.