Instead, I'm seeing a prompt 'Worker login' which doesn't seem to correspond to the rig id account that has been defined already...
Have you tried editing the .conf file manually by directly accessing the drive from another PC?
If not then I would recommend checking those files to see what is written to them... it should give you an idea of where you're at.
Which config file in what location?
Sorry, I'm totally newb in Linux mining...
Stick your Hive USB into a Windows box. You will probably be prompted to format a drive. Say no. Two partitions for the USB should have shown up. One can be accessed via Windows. One file has a name similar to "sample rig config". Open this file in Notepad. There will be two variables here. One is something like "rig_id" and the other is "password". These values were created in your Hive OS dashboard when when you added a rig. You need to insert your "Rig ID" for the miner from your Hive web dashboard. Same for the password. Then you need to save the file as "rig.conf" but make sure that .txt is not appended to the filename. Put the stick in your rig and boot.
This is how you get around having to have a monitor and keyboard hooked up to a rig when you set it up.