Nozzle size set on printer would not sync, switching to non-lan-mode made the change appear in Bambu Studio 
Just fyi, maybe it helps someone
Unfortunately, My company requires us to bein LAN-only and blocks most network access to the printer so…
I can’t have 2 nozzle sizes on the printer, even if I am printing with a single one in the print. The slicer only allows me to choose having left/right nozzle the same size, and thus the printer errors when it sees the gcode file specifies 2 of the same size.
Anyone have another work-around?
A follow-up for future readers:
Using Bambu Studio version 2.6.0.51, it still forces you to set the same nozzle size for both left and right extruders. It is possible you can get different nozzle sizes by syncing, but I have no idea to do this in non-networked setup.
However, when going to slice, you must select custom filament grouping and ensure the filament you are using goes to the correct intended extruder. It seems as the object is painted with the correct filament number (e.g. Filament #1), and the filament number is assigned to the the correct extruder (e.g. Left nozzle, 0.2mm) that matches what is on the printer in that left/right slot (0.2mm left, 0.4mm right), then it will proceed with the print, even if the other hotend is a mismatch between the slicer (0.2mm, Right) and the machine(0.4mm Right).