Hello,
It's how I use my Max2 on Linux :
https://www.mobileread.com/forums/sh...&postcount=382 and I use 'mtp-tools' and 'gmtp'.
You could try with 'gmtp'. The you push the "Connect" button, be very patient.
Before anything, remove all other USB devices...
Gmtp was my first tools as simple 'user', not 'root'.