hi i encountered the problem of hard drives having underscore 1 added on updating to 1.6.1 even when i rolled back to 1.5.4 this remained but found this article on community forum helped renameing them back to original https://community.zimaspace.com/t/zimaos-v1-6-1-released-fix-for-usb-devices-not-auto-mounting/8463/9
the answer by Dina was spot on work around just be carfull not to format the drive and remember to do it in 1.6.1 you can not in 1.5.4