@DanTarl
Hi DanTarl - I created a forum account just to thank you for this tip.
I was frustrated by my zero delay encoder going in to disconnect/reconnect loop (led flashing) while using MAME on Ubuntu v22. Adding this to the Grub Linux boot parameters fixed the problem immediately.
The line now looks like this:
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash usbhid.quirks=0x0079:0x0006:0x00000400"
Detailed instructions for editing Ubuntu boot parameters here.
Thanks again - solving this seemed like such a longshot!
Paul