The way the license system is supposed to work, nothing about the user is used when generating the fingerprint for the machine. The software generates a machine fingerprint, submits it to the server which checks to see if any users on that key have the same fingerprint. If they do, it shouldn’t consume a seat, because licensing is per-computer.
In your “user-A / computer-B” scenario above, do both of the computers have the ldata file in the LightBurn folder?
@DTTech - Are you using the command-line process for activating the floating license? (outlined here: Licensing Setup - Configuring different license options)