with a mac host running a mac guest
I use an HHKB 2 keyboard. Works great with a Windows VM and Ubuntu VM on a Catalina macOS host.
The problem is with a Catalina macOS guest, on a Catalina macOS host.
The problem is, shift-2 no longer gives me an @ as I expected. After poking around, I discovered my [ key had become my @ key.
I discovered that my shift-2 now produced a “ symbol — the printer’s open-quote.
I opened up system’s preference on macOS Catalina, in the VM, and discovered in keyboard input sources the reason for the problem — they don’t map correctly to my HHKB. What is the @ key doing over on the side?
When you press the shift-2 key in the diagram, sure enough, you get the printer’s open-quote.
More disturbingly, the US keyboard can report different key layouts at different times. Sometimes you see  in place of @[, for example, until you whack the shift key a few times.
Hoping Parallels can help with this.